Mobile Programming Midterm

Wifi

802.11 a/b/g/n = wlan standards a/b/g/n are different bandwidths a facility allowing computers, smartphones, or other devices to connect to the Internet or communicate with one another wirelessly within a particular area. measures signal strength of visible access points, uses a location database service

Android application components

Activity = single user-focused task, typically implemented to handle the presentation & control of a specific screen, only 1 active at a time Service = task that doesn't require user interaction that runs in background, runs on main thread unless offloaded, higher priority than inactive/invisible activities, can be bound to app components Broadcast receiver = application intent listeners, your application to react to specific system wide broadcasted intents Content Provider = manages secure access to a shared set of application data, used to expose internal app data to other apps (use other thread)

In-app advertising

Ad formats = banners ads/interstitial ads/native ads/incentivized ads pricing models: cost per impression (CPM) views click through (cost per click) cost per action/acquisition = advertiser pays for each specified action - for example, an impression, click, form submit cost per install = based on user installing an app on their mobile phone

Sandbox

Aka home directory for iOS app directory that holds application bundle, tmp, documents, library, cache data can be stored locally here

Touch ID Authentication (IOS)

Allows 5 fingerprint attempts before a passcode is required. Can be used to tell SE to release keychain items (credit card, etc.) for use (i.e. purchase) Operation: Raster of fingerprint is sent to encrypted memory in SE, temporarily use to create a map of dermal ridge flows, then map is stored without user id. Data is not sent to Apple

Garbage Collection in Android

As you allocate more objects in your app, you will force a periodic garbage collection, creating little "hiccups" in the user experience Automatically done

RSA vs. ECC

Asymmetric encryption: one public, one private key RSA & ECC RSA = Rivest, Shamir, and Adelman, the inventors of the technique uses 2 keys, one public, the other private uses keys are related to each other by 3 numbers: "d," "e," and "n" issue = Symmetric Key Encryption requires private keys to be sent securely before any communication can take place. ECC = elliptic curve cryptography Successively adding a point to itself ->Find where tangent to point crosses the curve. -> Reflect over x-axis ->Repeat. -> Repetition Count is private key -> Final point is public key -> Initial point is public! (This is all computed in modulus) Y2 = X3 + AX + B Curve Observations = always symmetric about x-axis, always has 3 inflection points

secure boot chain (IOS)

Boot ROM code (burned during chip fabrication) -> Apple Root CA public key (in ROM) verifies LowLevel Bootloader (LLB) is signed by Apple -> Unique ID ingrained into silicon (ECID) -> LLB verifies, loads, and runs iBoot -> iBoot verifies, loads, and runs iOS kernel A7 chips — Secure Enclave also booted up. In Case of Failure = "Connect to iTunes" display or Enter Device Firmware Upgrade mode

Where can data persist safely in iOS apps?

Caches can be lost during backups Tmp can be lost during backups or during normal use Document directory, app bundle, library directory

CSS

Cascading Style Sheets Style Style defines the appearance of an element Style sheet is a series of rules/styles for an entire site

Ephemeris data

GPS satellite continuously transmits its own position

Almanac data

GPS satellite transmits info about the constellation over radio waves, use almanac data to predict which satellites are nearby when they're looking for GPS signals (not very accurate, can be months old)

HTML5

Hypertext Markup Languages Content combination of content and markups (tags & descriptive attributes) that define how a document should appear in a browser HTML5 specific = new form features (url,email, date), global attributes (hidden, dropzone), new events (onerror, onscroll), new tags (<time>, <nav>)

Xcode

Integrated interface builder = graphically lay out your app's interface widgets (views), connects your interfaces view to your code's model Storyboard builder = defines relationship between views, create + design new views

HTML5 mechanisms for persistence

Local storage = data persist even if user leaves the site or closes the browser Session storage = window closes -> data is removed, will survive a refresh Database storage (local = WebSql, IndexedDB, server = remote = MySQL, SimpleDB) File Storage (XML & JSON) XML = standard data format that allows for simplified transport of data (parsing can be challenging) JSON = lightweight data-exchange format, easier to parse and less overhead file system API = large text/binary files can be created & stored, limited support, security risk, unstructured data (no search feature) Application cache = offline, added cache manifest file to every HTML file in your app

JavaScript

Logic A scripting language used by web browsers Considered multi-paradigm as it supports (OO concepts, Imperative programming functions)

web-based mobile application

Platform & device neutral Application runs in browser (no need to push updates, no need for app store, must be online to access app resources) Uses open, well supported web technologies (coded in browser rendered language - HTML5 w/ javascript) Limited access to device features (standards lag innovation) No access to native UI elements (getting the look & feel right can be difficult)

native mobile application

Platform specific (directly interacts w/ OS, access all hardware APIs, optimize performance) Better user experience App store deployment (binary executable download & store on device, offline support) Requires writing code in supported languages used supported enviornment

Monetizing applications

Purchase Price Subscription Fee In App-Advertising In App-Purchases 3rd Party Revenue Stream

user application security measures (IOS)

Randomly-Named sandbox directory. No tools for remote access included in kernel. Data shared between apps only via iOS services Address space layout is randomized.

Apple Pay

Secure Element (another chip like Secure Enclave) runs Java Card platform, compliant with financial industry standards for e-payments. NFC Controller Wallet — stores encrypted credit/debit card info Secure Enclave — manages authentication without using Apple servers Apple Pay Servers manage state of credit and debit cards. All transactions include a one-time dynamic security code not known to apple

Android mechanisms for persistence

Shared Preferences = store private primitive data in key-value pairs, common use is user settings Local Files (internal/external) = save a basic file, such as to store long sequences of data Static Application Resources = save raw files, strings, views Local Content Providers = exposes read/write access to your application data Local Database (SQlite) = read and write structured data in private database

Objective-c vs. java differences

Similarities = code is collected into methods defined on objects which are generated from class templates Has .h and .m files Different syntax for invoking methods (Java = MyObject.MyMethod(), Objective-C = [MyObject MyMethod];) Java = glass y = new Glass (A1,A2,A3);, Objective-C = Glass y = [Glass glassWithWidth:A1 height:A2 selfDestructProbability:A3]; Java = new Employee, Objective-C = [Employee alloc] Unlike java little automatic garbage collection

App bundle? tmp directory? Documents directory? Library directory? - what type of data each stores

Store this type of data: app bundle = no writing, way of packaging executable code, stores everything that the application requires for successful operation (info.plist, resources, executable) tmp directory = temp files only documents directory = user data library director = user defaults

Network Protocols

TCP = Transmission control protocol = connection-oriented, reliable service, data exchanges (files/emails/web) UDP = user datagram protocol = connectionless, unrealiable timely service (media streaming & gaming)

Platform

The hardware/software environment for laptops, tablets, smartphones and other portable devices

Mobile location based service providers

Time To First Fix (TTFF) is a measure of the time required for a GPS receiver to acquire satellite signals and navigation data, and calculate a position solution GPS based = calculates location from distance to 4 satellites, highest location resolution, slowest time to first fix (TTFF) Cell = measures signal strength of cell towers, uses a location database service, lowest location resolution, fastest TTFF Wifi = measures signal strength of visible access points, uses a location database service

User interface design

UI = the design and layout of the visual elements of a mobile/web app UX = the overall feel of a mobile/web app maintain consistency, provide clear navigation and simple instructions, be aware of mobile context, important elements should have enough contrast to be easily recognized under device limitations, leverage device ecosystem, don't forget landscape, learn user preferences over time, every input has value

unique device IDs

UID and device group ID (GID) are AES 256-bit keys; no software or firmware can read them — only sees results of encryption or decryption. UID ties data to particular device

GPS limitations

Unobstructed signals are required (need line of sight to satellite, can reflect off objects = multipath errors) Large power consumption Signal noise caused by atmospheric effects & electrical interference of receiver

UI user acceptance testing

User Acceptance Testing generally verifies that the deliverable meets the agreed upon requirements Make sure customer is able to understand flow of application and what actions to take

iOS mechanisms for persistence

User defaults Property Lists/Dictionaries SQLite Core data iCloud

What features does each iOS persistence tool provide?

User defaults = application to customize its behavior Property Lists/Dictionaries = convenient way to store, organize, and access standard types of data. SQLite = provide structured data set, private to application Core data = use to manage the model layer objects in your application. iCloud = syncing data among devices

Local Files (internal/external)

Uses standard Java I/O classes internal = refers to the apps private portion of the flash storage external = user mounted portion of the device typically used for public files that are visible to all Files can be cached or stored on a more permanent basis

3rd party revenue stream

a company purchases or brands your application. A great example is Under Armor's recent purchase of apps like MyFitnessPal and MapMyFitness.

Garbage collection

a form of automatic memory management attempts to reclaim garbage, or memory occupied by objects that are no longer in use by the program

Application programming interface (API)

a set of routines, protocols, and tools for building software applications. The API specifies how software components should interact and APIs are used when programming graphical user interface (GUI) components.

Activity lifecycle

active from onResume() to onPause(), Destroyable after onPause() Order = onCreate -> onStart() -→ onResume() -→ onPause() --→ onStop() -→ onDestroy()

Wireframing

basic screen sketches show key screen elements & functionality Not meant to fully specify the user interface Does not focus on style/color/content Allows you to quickly generate & easily demonstrate an interface w/o building one

authentication

be certain that the sender sent the message Authentification Alice "decrypts" using her private key Bob "encrypts" using Alice's public key Only Alice can possibly have sent the message •Secure & Authenticated -- Alice "decrypts" using her private key -- Alice encrypts using Bob's public key -- Bob decrypts using his private key -- Bob "encrypts" using Alice's public key -- Only Alice can possibly have sent the message, and only Bob can read it

What is persistence?

characteristic of state or data which outlives the process that created it

Hybrid mobile application

combines native development w/ web technology Significant portion written in cross web technologies Direct access to APIs provided through extension packs (native portion of app uses OS APIs to create embedded HTML rendering engine that serves as bridge b/t browser & device APIs)

Network Sockets

communication endpoint between two applications usually running two different machines Data flow b/t the sockets is called a stream = send either binary or unicode data Data is transmitted in specially sized packets Identified by an end-to-end transport protocol, an IP address and a port number

Location sensors

compass = instrument containing a magnetized pointer that shows the direction of magnetic north and bearings from it. GPS = satellite system that provides position, navigation, and timing (1 way transmission, 3-5 meter accuracy, clocks @ 1 nanosecond) GPS receiver calculates distance to satellite Performs trilateration using multiple satellites to determine speed/distance/elevation

Android manifest file

configuration file for the application, specifies application permissions, structured xml file for settings

Wifi Direct

connect directly to other devices over wi-fi w/o used a shared access point creates a wireless peer to peer (P2P) ad-hoc network discover devices that are w/in range and what services are offered on the device Promotes a more reliable, higher-speed, longer-range communication compared to bluetooth

Sensor fusion

describes the process of combining more than one sensors example = combining MEMS 3-axis gyroscope and the 3-axis accelerometer you can provide full 6 degrees of freedom

user centric design process

design for real ppl w/ real problems observation -> ideation -> design -> build -> test

Business Plan

detailed road map for converting a recognized opportunity into a profitable business persuades potential investors, need value proposition contributes to success of venture parts = executive summary, market analysis/strategy/plan, financial analysis/projections, product development plan

Geolocation

directions/route finding, location-based search/advertising/social interaction, tracking ppl and assets, augmented reality

encryption/decryption

encryption = Convert a message (cleartext) into blocks of numbers, then run an algorithm on them using a "key" (another big number) that transforms them into an unreadable format (ciphertext) by anyone other than holders of a "key." Symmetric encryption: two private keys (DES, AES) Asymmetric encryption: one public, one private key (RSA & ECC) send message so only intended receiver can read it decryption = process of taking encoded or encrypted text or other data and converting it back into text that you or the computer can read and understand.

Sensor types

environmental = measure various environmental parameters, such as pressure/illumination/humidity position = measure the physical position of a device such as bearing/orientation/proximity motion = measures acceleration & rotational forces along three axes location = determines the location of a device using GPS

The purpose/goal of a pitch

goal at the end is to have an immediate decision regarding the next steps

Motion sensors

gravity = measure force of gravity along x/y/z axis accelerometer = measure the acceleration (or force) applied to the device, at rest measure gravity, synthetic sensor will factor out the force due to gravity, measure changes in linear velocity in -x -y & -z axes gyroscope = measure rate of rotation around axes

Resources

holds non-code resources such as string/ constants/menus/colors/images all compiled and compressed into R class file Static resource file = read-only static file bundled w/ app

3D resolutions

lat, lon, alt and other data can be determined with 4 satellites Provides improved positional accuracy

Environmental sensors

light = visible on the face of the device, small opening, reports ambient light level w/ a 1 lux resolution camera barometer = measures atmospheric pressure microphone

Shared preferences

lightweight data-storage framework used to save and retrieve key-value pairs of primitive data types across user sessions Can be private to specific activity or shared across all components in an application Stored as an XML file in the protected application directory Uses = checking the first use of the app, login info, saving user preferences

Bluetooth Classic & low energy

low power, low bandwidth, short range, wireless data communication standard Uses the license-free 2.4 GHz ISM radio-frequency band (same frequency band as 802.11 b/g Wifi)

Position sensors

magnetometer = get compass heading/bearing measure strength + direction of magnetic field orientation = monitor the position of a device relative to the earth's frame of reference (specifically, magnetic north) proximity = visible on the face of the device (2 small openings), most are reporting the presence or absence of an object at a given distance, triggered on state transitions (near-to-far or far-to-near)

Android Platform Fragmentation

many different platform version of android OS out there, not forced to update

Design thinking

methodology used by designers to solve complex problems, and find desirable solutions for clients

Sensors

microphone, camera, location, orientation, proximity, light, pressure, accelerometer, heart rate

Cellular

mobile telephone system that uses a number of short-range radio stations to cover the area that it serves measures signal strength of cell towers, uses a location database service, lowest location resolution, fastest TTFF

Delegate (w/ respect to Model-View-Controller)

model -> controller (key value observing = controllers register for event notices from model) controller -> view (method/messaging for updating) view -> controller (delegates & events = delegate implements protocols) controller -> model (getters/setters)

Provisioning profile

need an app ID Use download button to get profile file Expires in 90 days Drop on xcode collection of digital entities that uniquely ties developers and devices to an authorized iPhone Development Team and enables a device to be used for testing

What are features of SQLite persistence tool?

no installation, no intermediary server process cross platform Exposes methods to manage a SQLite database Private to application

Model View Controller

organizes your interface/processing design/source code, encourages modularity in components & re-use in app redesigns model = core database, objects holding data, objects maintaining app state controller = coordinates model & view, contains UI logic of the app view = display objects, interactive objects

Orthogonal vs. nonorthogonal persistence

orthogonal = implemented by process's environment, no explicit program actions are required to retrieve or save state nonorthogonal = implemented through explicit actions in the process's program

Co-inventor

patentable invention is the result of inventive work of more than one inventor.

Intent

powerful asynchronous messaging mechanism used w/in or b/t applications, used to broadcast system wide messages, request action to be performed + data to be acted on, explicit or implicitly activate activities Store data in key-value pairs called extras, these intent extras implemented as bundle Implicit = allows anonymous application components to service intent requests @ run time (performed using filters defined for each application component)

Tools for financial analysis

pro forma balance sheet pro forma income statement profit & loss projected sales breakeven analysis

Executive summary

product description, key benefits/value proposition

Positioning

promote (a product, service, or business) within a particular sector of a market, or as the fulfillment of that sector's specific requirements

What is a cursor?

provides random read-write access to the result set returned by a database query.

Purchase price vs. subscription fee

purchase price is the cost to download the app subscription fee = reoccurring fee after a set amount of time

Elevator pitch

quickly sum up the unique aspects of your venture/idea in 30-60 seconds want to excite others with your passion and the story behind your idea tailored to a specific audience & outcome goal at the end is to have an immediate decision regarding the next steps

Prototyping (rapid/iterative)

rapid = test out the key technical features and user behaviors to determine the viability of an app (build it sturdy, build only what you need, build the experience not the technology) iterative = build some functionality into the app then ask users to try it and give feedback, use smoke and mirrors to test concepts, test beyond the lab, learn from interactions with real users

Raw vs. synthetic

raw sensors = physical, provides the raw data from an actual physical sensor (example = light,pressure) synthetic = virtual or composite, provides data from a combo of sensors or may manipulate the raw sensor data before reporting it (example = rotation vector, gravity)

Revenue vs. expenses

revenue = sales (direct/subscriptions, in-app purchases, advertising, 3rd party sales) determine ad revenue = # times/month app used, avg. duration of each session, how often ads are loaded, category of your app on website, platform your app is on fixed expenses = supplies, infrastructure, R & D, salaries/wages variable expenses =advertising, promotions, professional advisor fees, miscellaneous

Closed-platform development process

run signed apps from a single trusted source (iOS) control who runs what apps on what devices pro = limit possibilities of bad codes running wild (apple/google have global kill switches) con = limit possibilities of what is "good code"

Android Emulator

runs full android software stack, defined by android virtual device (AVD), can't make calls/no usb connections/can't connect to network/no battery charge support

Differentiation

separating your product from the rest of what is out there has unique purpose

W3C

set standards for CSS CSS3 is the current standard (multi-column grid layouts, rounded corners, transparent colors)

Geofencing

setup geographic boundaries around specific locations and receive notifications when the user enters or leaves those areas Adjusts location updates based on user's proximity to the geofence & user's activity

near field communication (NFC)

short-range wireless communication standard (operates on low frequency band, able to transmit small amts of data) built upon radio-frequency identification (RFID) uses electromagnetic fields generated by radio waves to transfer data between two RFID-enabled devices (requires NFC chip) NFC tags = read/write small amounts of data to memory, no battery (activated w/ induction)

Simulator vs. emulator

simulator = duplicates external appearance or behavior of a system w/ no guarantee that his is using the same internal techniques as the original system's hardware/software emulator = behaves like real phone, runs its OS, adheres to all system rules

Storyboarding/use case

storyboarding = collection of wireframes that quickly &easily demonstrate a primary sequence of interactions/events to successfully achieve useful in gathering feedback early in the design phase (navigation w/o having to code) supports defined use cases = written description of app behavior from user point of view, outlines any alternative paths, lists any require pre/post conditions, can be used to help classify/prioritize features

Field testing/field trials

test (something) in the environment in which it will be used

Marketing mobile apps

traditional promotion = web site w/ good screen shots/video/comments, social media, PR release, competitions app store optimization = review, free app a day, rankings, top charts alternate app stores paid advertising = affiliate markets apple iAd, google adMob social media = twitter's app cards, Facebook app install Ad, Pinterest App pins

Geocoding

translates GPS location data to/from addresses or places of interest (street address --> lat/lon) reverse geocoding = (lat/lon) ---> stress address

Developer certificate

uniquely identifies you = sign your software as coming from you, verify your device's profile you are who you say, apply through apple developer portal Mac need keychain access utility application

In-app purchases

usage = offer limited usage/bandwidth/hours/storage space time = free trial of fully functional app for limited amount of time functionality = pay for virtual items, speed up, content, add-ons, upgrades, services user experience = free app has adds, pay to remove can have combination of the above

context sensitivity

user interface is one which can automatically choose from a multiplicity of options based on the current or previous state(s) of the program operation when operating correctly, should be practically transparent to the user without explanation