Mobile App Development Flashcards

Question 1

What is a native mobile app, and how does it differ from other app types?

Accepted Answer

A native mobile app is software written for one mobile operating system using that platform's own languages and tools. It offers strong performance and direct access to hardware features such as the camera and sensors. The main drawback is that separate versions must be built and maintained for each platform, which raises cost.

Question 2

What is a progressive web app, and how does it differ from a native app?

Accepted Answer

A progressive web app is a website built with web technologies that can be installed to a home screen and work offline. It runs in a browser rather than being downloaded from an app store, so one codebase serves many devices. Its limitations include weaker hardware access and less consistent behavior across browsers.

Question 3

Why do mobile devices impose stricter limits on battery and processing power than desktops?

Accepted Answer

Mobile devices are limited because they run on rechargeable batteries and compact cases that restrict power supply and heat removal. Developers must write efficient code, avoid unnecessary background work, and limit network and screen activity. Designing with these constraints keeps apps responsive and prevents them from draining the battery quickly.

Question 4

What is the difference between an app's foreground and background states?

Accepted Answer

The foreground state is when an app is open and displayed to users, while the background state is when it is running but not visible. Operating systems restrict background activity to protect battery life and privacy. Apps must handle transitions between these states, saving data and pausing tasks when they move to the background.

Question 5

What is an application lifecycle, and why do developers need to understand it?

Accepted Answer

The application lifecycle is the set of states an app moves through, from launch through suspension to termination, as set by the system. Developers need to understand it so they can save progress, release resources, and restore the user's place when the app returns. Ignoring lifecycle events causes lost data, crashes, or wasted battery.

Question 6

What role does the user interface play in determining whether a mobile app succeeds?

Accepted Answer

The user interface is the visible part of an app that people use to complete tasks, so it shapes first impressions and continued use. A clear, consistent interface helps users find features and reduces errors. Poor navigation or cluttered screens often lead users to abandon an app, regardless of how capable its code is.

Question 7

What is responsive layout design, and why does it matter on phones and tablets?

Accepted Answer

Responsive layout design is an approach where screen elements resize, reflow, or rearrange to fit different screen sizes and orientations. It matters because mobile devices vary widely in width, height, and pixel density. A layout built for one size can break on another, leaving text cut off or buttons hard to tap.

Question 8

Why should touch targets be sized generously in a mobile interface?

Accepted Answer

Touch targets should be sized generously because fingers are much larger and less precise than a mouse pointer. Small or closely spaced controls lead to accidental taps, frustration, and slower task completion. Common guidance is to keep interactive elements large enough and separated enough that a person can tap the intended one without effort.

Question 9

What are the most common navigation patterns used in mobile apps?

Accepted Answer

The most common mobile navigation patterns are tab bars, navigation stacks, drawers, and bottom sheets. Tab bars give users quick access to a few top-level sections, while stacks move users deeper into a hierarchy and back. Drawers hide secondary options, and bottom sheets present temporary choices near the thumb.

Question 10

Why is consistency important across the screens of a single app?

Accepted Answer

Consistency lets users learn one part of an app and apply that knowledge elsewhere, reducing the effort needed to understand each new screen. Repeated placement of buttons, icons, colors, and wording makes actions predictable. When elements behave differently in similar situations, users hesitate, make mistakes, and may stop trusting the app.

Question 11

What is accessibility in mobile app design, and which groups does it help?

Accepted Answer

Accessibility means designing apps so people with a range of abilities can perceive, understand, and operate them. It helps users who are blind or have low vision, people with motor or cognitive differences, and people using one-handed or in bright light. Practices include labeling controls for screen readers, sufficient color contrast, and scalable text.

Question 12

How does clear feedback, such as loading indicators and confirmations, help users?

Accepted Answer

Feedback tells users that the app has received their input and what is happening now. Loading indicators reduce uncertainty during slow operations, while confirmations show that an action such as sending a message succeeded. Without feedback, people tap repeatedly, assume the app is broken, or submit duplicate requests.

Question 13

What does onboarding aim to accomplish when a new user opens an app for the first time?

Accepted Answer

Onboarding aims to help a new user understand the app's purpose and reach their first meaningful success quickly. It may include a brief tour, a permission request, or an account invitation. Good onboarding asks for only what is necessary, since long setup steps cause people to leave before they see any value.

Question 14

Why do platform design guidelines matter when building an app for iOS or Android?

Accepted Answer

Platform design guidelines describe the standard components, gestures, and behaviors that users expect on each operating system. Following them makes an app feel familiar and reduces the learning curve for people who use that platform daily. Ignoring them can make an app seem unpolished or confusing, even when its features are strong.

Question 15

How should color and contrast be used so that text remains readable on a phone?

Accepted Answer

Text should have enough contrast against its background to remain readable in varied lighting, including glare outdoors. Color should never be the only way to convey meaning, so icons, labels, or patterns should reinforce status changes. Users with color vision differences or low vision depend on these choices to understand the screen.

Question 16

What is the purpose of a prototype in the mobile app design process?

Accepted Answer

A prototype is a simplified, interactive model of screens and flows that lets designers and stakeholders test an idea before full development begins. Low-fidelity sketches are quick to change, while high-fidelity prototypes look and behave closer to the finished product. Testing prototypes with real users reveals confusing steps early, when changes are cheap.

Question 17

What is a cross-platform framework, and what problem does it try to solve?

Accepted Answer

A cross-platform framework lets developers write one shared codebase that produces apps for more than one mobile operating system. It tries to solve the cost and effort of maintaining separate native projects for each platform. Trade-offs include possible performance limits and the need to handle platform-specific features through extra code.

Question 18

What is a software development kit, and what does it typically include?

Accepted Answer

A software development kit is a collection of libraries, tools, documentation, and sample code that helps developers build software for a platform or service. For mobile work, it typically includes interfaces for device features, build utilities, and emulator or simulator support. The official kit helps an app call platform services correctly.

Question 19

What is the difference between an emulator and a physical test device?

Accepted Answer

An emulator is software that imitates a mobile device on a computer, letting developers test without owning every model. A physical test device offers true hardware behavior, including real sensors, camera quality, battery use, and touch response. Most teams use both, since emulators are fast but physical devices reveal problems that imitation can miss.

Question 20

What role do version control systems play in a mobile development team?

Accepted Answer

Version control systems record every change to source code, so teams can track edits, compare versions, and undo mistakes. They allow several developers to work on the same project in separate branches before merging their changes. Version history also supports code review and helps teams identify when and why a bug was introduced.

Question 21

Why must mobile apps request permissions, and how should they do it?

Accepted Answer

Mobile apps must request permission before accessing protected resources such as location, contacts, the camera, or notifications. Operating systems enforce these requests so users control their personal data and device features. Good practice is to ask only when a feature needs the permission, and to explain the reason clearly in context.

Question 22

What is the difference between a debug build and a release build?

Accepted Answer

A debug build includes diagnostic information, logging, and tools that help developers find and fix problems during development. A release build is optimized for speed, size, and security, with debugging aids removed for distribution to users. Testers and developers should never assume that behavior in one build will match the other.

Question 23

How do package managers and dependency libraries affect a mobile project?

Accepted Answer

Package managers download and install third-party libraries that a project depends on, such as networking or image loading code. They save development time, but every dependency adds maintenance, security, and app size considerations. Developers should review licenses, keep versions updated, and remove libraries that are no longer needed.

Question 24

What is the difference between local storage and remote storage in a mobile app?

Accepted Answer

Local storage keeps data on the device itself, so it remains available without a network connection. Remote storage keeps data on servers, allowing it to be shared across devices and backed up centrally. Most apps combine both, caching what users need on the device while keeping the authoritative copy on a server.

Question 25

Why do mobile apps often need to work offline, and how is that usually handled?

Accepted Answer

Apps need offline support because mobile connectivity can be slow, intermittent, or unavailable, such as on trains or in remote areas. Apps handle this by storing data locally and queuing changes made while offline. When the connection returns, the app synchronizes queued changes with the server and resolves any conflicts.

Question 26

What is an API, and how do mobile apps typically use one?

Accepted Answer

An API, or application programming interface, is a set of requests and responses that lets one program access another's data or services. Mobile apps call web APIs to fetch content, submit user input, or authenticate accounts. The app sends a request, usually in a common data format such as JSON, and reads the reply.

Question 27

What is JSON, and why is it commonly used between mobile apps and servers?

Accepted Answer

JSON, short for JavaScript Object Notation, is a lightweight text format for representing structured data as key and value pairs. It is commonly used between mobile apps and servers because most programming languages can parse it easily. Its compact, readable structure keeps messages small and simple to debug.

Question 28

Why should an app encrypt network traffic and sensitive data stored on the device?

Accepted Answer

Encryption protects information from being read or altered by anyone who intercepts it or gains access to the device. Network traffic should use secure protocols such as HTTPS, and sensitive stored data should be kept in the platform's protected storage. These steps help protect passwords, personal details, and payment information from exposure.

Question 29

What is a common way to handle data that changes on both the device and the server?

Accepted Answer

A common approach is to record the version of each change and merge updates according to a rule. Last-write-wins keeps the latest edit, while other strategies merge fields or ask the user to choose. The chosen rule should match the app's purpose, since losing a user's edits is worse than slow syncing.

Question 30

How does caching improve the performance of a mobile app?

Accepted Answer

Caching stores copies of frequently used data so the app can show it without repeating slow network requests. This reduces waiting time, lowers data usage, and keeps screens usable during brief connection drops. Caches must be refreshed or expired carefully, because stale content can mislead users or show outdated information.

Question 31

What is the difference between unit testing and UI testing in a mobile project?

Accepted Answer

Unit testing checks small pieces of code, such as a function or class, in isolation. UI testing drives the app through its screens, simulating taps and text entry to confirm that workflows behave as expected. UI tests are slower and more fragile, so teams favor many unit tests and fewer UI tests.

Question 32

Why is testing on multiple screen sizes and operating system versions important?

Accepted Answer

Users run apps on many device models, screen sizes, and operating system versions, and behavior can differ among them. A layout or feature that works on one device may clip, crash, or behave unexpectedly on another. Testing across a representative range helps teams catch these differences before users do.

Question 33

What is beta testing, and how does it differ from internal quality assurance?

Accepted Answer

Beta testing releases a finished app to a limited group of outside users who try it in their own settings. Internal quality assurance is performed by the development team or testers working under controlled conditions. Beta feedback reveals real-world issues, such as unusual devices, network conditions, or habits that internal testers may not expect.

Question 34

What steps are involved in publishing an app to a mobile app store?

Accepted Answer

Publishing usually involves creating a developer account, preparing a signed release build, and providing store listing details such as descriptions, screenshots, and privacy information. The developer uploads the build, submits it for review, and responds to issues the store raises. Once approved, the app can be released to users in full or in stages.

Question 35

Why do app stores ask for privacy information and review submissions?

Accepted Answer

App stores ask for privacy information so users can understand what data an app collects and how it is used before installing. Review helps catch crashes, broken features, misleading descriptions, and policy violations before an app reaches the public. These checks protect users and the store's reputation.

Question 36

What is crash reporting, and why do teams monitor it after release?

Accepted Answer

Crash reporting automatically collects details about app failures, such as the error type, stack trace, device model, and operating system version. Teams monitor these reports after release because real users encounter problems that testing did not reveal. Reviewing crash trends helps prioritize fixes for the issues that affect the most people.

Question 37

Why do mobile developers need to plan for updates that users never install?

Accepted Answer

Developers plan for this because many users delay or skip updates, leaving old versions in use for long periods. Developers must therefore keep backend services compatible with previous app versions and avoid breaking changes in data formats. Planning for this reality prevents older installations from failing when the server or data model changes.

Question 38

What should a team do when a critical bug is discovered after an app has been released?

Accepted Answer

The team should first assess the bug's severity and how many users it affects, then decide whether a fix can wait for a regular update. For serious problems, it should prepare a patch quickly, test it on key devices, and submit it through the store's expedited process where available.

Question 39

Why is it important to collect analytics responsibly in a mobile app?

Accepted Answer

It matters because analytics can improve an app while also exposing personal behavior. Collecting responsibly means gathering only what is needed, explaining it in the privacy disclosures, and respecting user choices about tracking. Trust is easily lost when people feel that their behavior is watched without clear consent.

Question 40

How do teams plan ongoing maintenance after an app launches?

Accepted Answer

Teams plan maintenance by scheduling regular releases for bug fixes, security patches, and operating system compatibility updates. They track performance, crash rates, and user reviews to decide which improvements matter most. Dependencies, certificates, and backend services also need periodic review, since neglected components can eventually stop working.

Mobile App Development Flashcards

1Mobile App Fundamentals

2User Interface and Design

3Platforms and Development Tools

4Data, Networking and Storage

5Testing, Release and Maintenance

Learning Resources