Mobile App Development Release and Operations Syllabus

Outline the high-level steps to submit an app to the Apple App Store.

(1) Register the App ID and create the app record in App Store Connect, (2) archive and upload a signed build via Xcode/Transporter, (3) fill in metadata, screenshots, pricing, and privacy details, (4) attach the build and submit for App Review, (5) release manually or automatically after approval.

What is the Google Play Console and what does it manage?

Google's web portal for publishing and managing Android apps: uploading AABs, managing release tracks, store listing, pricing, content rating, data safety, staged rollouts, and viewing Android vitals, ratings, and revenue.

Since August 2021, what artifact format does Google Play require for new apps and why?

The Android App Bundle (.aab) instead of a universal APK. Google Play uses it to generate optimized, device-specific APKs (split by ABI, density, language) via Dynamic Delivery, reducing download size.

What is the Data Safety section (Play) / Privacy Nutrition Label (App Store)?

A store-required disclosure of what user data an app collects, how it is used, whether it is shared with third parties, and whether it is linked to the user's identity, shown to users on the store listing before download.

Name three common reasons Apple rejects apps under the App Review Guidelines.

Crashes/bugs and broken functionality (Guideline 2), privacy violations or missing privacy policy (Guideline 5), and using private APIs or misleading/placeholder content. Also common: requiring external payment for digital goods instead of IAP, and insufficient app content ('minimum functionality').

Under Apple's guidelines, when must developers use In-App Purchase versus external payment?

Digital goods and services consumed within the app (subscriptions, unlocks, virtual currency) must use Apple's In-App Purchase. Physical goods and real-world services (e.g. ride-hailing, food delivery) must NOT use IAP and use other payment methods.

What is ASO (App Store Optimization) and what are its two broad goals?

ASO is optimizing an app's store presence to improve visibility in search/browse and to increase the conversion of impressions into installs. The two goals: (1) rank higher / be discoverable (keywords), and (2) convert visitors (icon, screenshots, ratings).

List the main on-metadata ASO factors a developer controls.

App title/name, subtitle (iOS) / short description (Android), keyword field (iOS, 100 chars), long description, app icon, screenshots and preview video, category, and (indirectly) ratings and reviews prompts.

Contrast how iOS and Android handle keywords for store search.

iOS has a dedicated 100-character keyword field (comma-separated, not shown to users) plus title/subtitle. Android has no keyword field; Google Play indexes the title, short description, and full description text for search relevance.

What is crash reporting and name two widely used mobile crash reporting tools.

Automatic capture and aggregation of app crashes/exceptions with stack traces, device state, and breadcrumbs so developers can diagnose and prioritize fixes. Common tools: Firebase Crashlytics and Sentry (also Bugsnag, App Center).

Define crash-free users rate and give a common release quality target.

$$\text{Crash-free users} = \frac{\text{users with no crash}}{\text{total active users}} \times 100\%$$ Many teams target $99.9\%$ or higher crash-free users as a release-health gate.

Why must you upload dSYMs (iOS) or mapping.txt (Android) for crash reporting?

Release builds are stripped/obfuscated, so raw crash stack traces are unreadable addresses. dSYM files (iOS) and the ProGuard/R8 mapping.txt (Android) let the crash reporter symbolicate/deobfuscate traces back to readable method names and line numbers.

Distinguish an event, a screen view, and a user property in mobile analytics.

An event is a discrete user action (e.g. 'add_to_cart') optionally with parameters; a screen view records which screen the user is on; a user property is a persistent attribute of the user/device (e.g. subscription tier, country) used for segmentation.

Define DAU, MAU, and the stickiness ratio.

DAU = Daily Active Users, MAU = Monthly Active Users. Stickiness measures engagement frequency: $$\text{Stickiness} = \frac{\text{DAU}}{\text{MAU}} \times 100\%$$ Higher values indicate users return more often; $20\%$ is a common baseline.

What is a retention curve and what is Day-N (e.g. D1/D7/D30) retention?

A retention curve plots the percentage of a cohort still active N days after install. D1/D7/D30 retention are the share of new users returning on day 1, 7, and 30. The curve typically drops sharply then flattens; the plateau indicates the core loyal base.

What is a funnel analysis in product analytics?

Tracking the sequence of steps toward a goal (e.g. view -> add to cart -> checkout -> purchase) and measuring drop-off at each step, so teams can identify where the largest share of users abandon the flow.

What is a feature flag (feature toggle) and give two benefits.

A configuration switch that enables/disables a feature at runtime without a new app release. Benefits: decouple deploy from release, enable gradual/percentage rollouts, run A/B tests, and kill a broken feature instantly (a 'kill switch').

What is Remote Config and how does it differ from a feature flag?

Remote Config is a cloud-stored set of key-value parameters an app fetches to change behavior/appearance without an update. A feature flag is a boolean subset of remote config; remote config more broadly can set strings, numbers, colors, and thresholds, and target user segments.

Explain the role of a kill switch in mobile operations.

A remotely controlled flag that lets the team disable a feature, endpoint, or the whole app path in production immediately when a critical bug, security issue, or backend failure is discovered, avoiding an emergency store release.

What are Over-the-Air (OTA) updates for apps, and what is a key store restriction?

OTA updates push new code/assets (e.g. JS bundles in React Native/Expo, or web assets) to installed apps without a store submission. Restriction: both stores forbid OTA updates that change the app's core purpose or add features outside the reviewed scope; only bug fixes/content within the original scope are allowed.

Compare native store updates with OTA (CodePush/EAS Update) updates.

Store updates can change native code but require review and user download; they are slow. OTA updates are instant and reviewless but limited to interpreted/JS/asset layers and cannot modify native binaries or bypass guidelines.

Classify the standard IAP product types on the app stores.

Consumable (used once, repurchasable, e.g. coins), Non-consumable (bought once, permanent, e.g. remove ads), Auto-renewable subscription (recurring access), and Non-renewing subscription (fixed-period access, no auto-renew).

What is a subscription free trial and an introductory offer?

A free trial gives full access for a period at no charge before the first billing; an introductory offer gives a discounted price (pay-as-you-go or pay-up-front) for an initial period to new subscribers. Both are configured per-subscription in the store.

What is the typical app store commission on IAP and subscriptions, including the Small Business reduction?

The standard commission is $30\%$. Under Apple's Small Business Program and Google Play's tiers, it drops to $15\%$ for developers earning under \$1M/year, and Apple charges $15\%$ on auto-renewable subscriptions after the subscriber's first year.

Define churn rate and its relationship to average subscription lifetime.

Churn is the fraction of subscribers who cancel in a period: $$\text{Churn} = \frac{\text{cancellations}}{\text{subscribers at start}}$$ Average customer lifetime in periods is approximately $\frac{1}{\text{churn rate}}$.

Write the formula for Customer Lifetime Value (LTV) in a simple subscription model.

$$\text{LTV} = \frac{\text{ARPU}}{\text{churn rate}}$$ where ARPU is average revenue per user per period. Equivalently, $\text{LTV} = \text{ARPU} \times \text{average lifetime}$. A viable business generally needs $\text{LTV} > \text{CAC}$ (customer acquisition cost).

Compare the main in-app advertising formats: banner, interstitial, rewarded, and native.

Banner: small persistent strip, low CPM, low disruption. Interstitial: full-screen ad at natural breaks. Rewarded: user opts in to watch for an in-app reward, high engagement/eCPM. Native: ad styled to match app content for seamless integration.

Define CPM, CPC, and eCPM in mobile advertising.

CPM = cost per mille (per 1000 impressions); CPC = cost per click. eCPM normalizes any model to per-1000-impression revenue: $$\text{eCPM} = \frac{\text{total earnings}}{\text{impressions}} \times 1000$$ It lets you compare ad networks/formats on one scale.

What is ad mediation and waterfall vs header bidding?

Mediation routes ad requests among multiple networks to maximize fill and revenue. A waterfall asks networks in a fixed priority order until one fills; header/in-app bidding runs a real-time unified auction so all networks bid simultaneously, typically yielding higher eCPM.

What distinguishes a push notification from an in-app message, and why get consent?

A push notification is delivered by the OS even when the app is closed (via APNs on iOS / FCM on Android); an in-app message shows only while the app is open. iOS requires explicit user opt-in (and Android 13+ needs POST_NOTIFICATIONS permission), so respecting consent preserves opt-in rates and avoids uninstalls.

Define push CTR and a healthy retention practice for notification frequency.

Push click-through rate: $$\text{CTR} = \frac{\text{notifications opened}}{\text{notifications delivered}} \times 100\%$$ To aid retention, personalize and segment messages, respect quiet hours and frequency caps, and use behavior triggers rather than blasting all users, which reduces opt-outs and uninstalls.