ASO Guides
The ASO Glossary: 60+ Terms Every Indie Developer Should Know (2026)
Every ASO term from App Privacy to Vanity URL, defined plainly. Cross-linked to the 18 deep-dives and 4 free tools that go with each term.
The ASO Glossary is a reference, not a read-straight-through. Indies coming to App Store Optimization get stuck on terminology more than on strategy — what’s the difference between subtitle and promotional text, what’s a Privacy Manifest, which binary format does which store want. This page defines the 60+ terms that matter across submission, metadata, testing, and post-launch.
Each term is one sentence. Click the term header to jump to the deeper post on that topic. Terms are grouped by theme in case you want to learn the vocabulary for a specific area all at once.
If you’re new to ASO overall, start with the ASO playbook for indie developers — then come back here for the vocabulary.
Metadata & listing
App Name
The app’s primary title as shown on the product page and home screen. 30 characters on both iOS and Google Play. Heavily indexed for search ranking. See the ASO playbook for the title formula.
Subtitle (iOS)
A 30-character field below the app name. Indexed for search ranking with high weight. The highest-leverage 30 characters on your iOS listing. Use the subtitle helper for proven patterns.
Short description (Play)
An 80-character Play-only field that sits above the full description on the product page. The primary conversion hook on Google Play. Covered in the App Store vs Google Play listing requirements post.
Keywords Field
iOS-only, 100-character comma-separated string in App Store Connect. Hidden from users; used by Apple for search matching. The Apple keywords field deep-dive covers every rule.
Promotional Text
iOS-only, 170 characters, updatable without app review. Sits above the description. Not indexed for ranking — conversion only. See the promotional text guide.
Description
4,000-character field on both stores. Indexed for ranking on Google Play only. The first three lines are the conversion hook on both stores — most users never tap “more.”
Release Notes / What’s New
iOS What’s New (4,000 chars) and Play Release notes (500 chars) appear to existing users on the update prompt. Conversion surface, not indexed. See the release notes best practices post.
Feature Graphic (Play)
A required 1024×500 PNG or JPG on Google Play that sits above the short description. Apple has no equivalent. No device mocks or call-to-action text allowed.
In-App Purchase Names
Indexed by Apple for search ranking. A rarely-exploited opportunity to surface extra keywords through IAP titles.
Developer Name
Apple indexes it for brand-search ranking. Distinct from the legal entity name on the account.
Visual assets
App Icon
1024×1024 PNG on iOS (no alpha), 512×512 PNG on Play (alpha allowed). Must pass the 40-pixel silhouette test. See the app icon design guide.
Liquid Glass Variants
iOS 26 (2025) icon variants — light, dark, and tinted. Optional but increasingly expected for premium apps.
Adaptive Icon (Android)
Android 8+ icon format with separate foreground and background layers that the launcher composites into device-specific shapes.
Screenshot
2–10 per device class on iOS; 2–8 per device class on Play. First screenshot owns the install decision. See screenshot sizes reference.
App Preview Video
iOS: up to 3 per device class, 15–30 seconds each. Play: one video per listing, 30 seconds to 2 minutes, hosted on YouTube.
Safe Zone
Design area within which critical graphic elements should sit to avoid clipping when the launcher applies corner rounding or masking.
OG Image
1200×630 image shown when your app’s marketing page is shared on social networks. Not an App Store asset; relevant for the marketing site side.
40-Pixel Silhouette Test
Rendering an icon at 40 pixels and checking that the silhouette reads clearly at that size — where most users actually see the icon.
Submission & binary
IPA
iOS App Package. The ZIP archive iOS apps ship as. Only the Apple App Store accepts IPAs. See the IPA vs APK vs AAB deep-dive.
APK
Android Package. The classic Android binary format. Still accepted by non-Play stores; Google Play requires AAB for new apps since August 2021.
AAB
Android App Bundle. Google’s required format for new Play apps since August 2021. Play slices it per device for smaller installs.
Privacy Manifest
A PrivacyInfo.xcprivacy file bundled in iOS apps and SDKs declaring data collection and required-reason API usage. Enforced since May 2024. See the privacy manifest guide.
xcprivacy
The plist file format and file extension of the Privacy Manifest. PrivacyInfo.xcprivacy.
Required-Reason API
One of the 5 iOS API categories (file timestamp, system boot time, disk space, active keyboards, user defaults) that requires a declared reason code in the Privacy Manifest.
Target SDK / Target API Level
The OS version your app is built against. Apple enforces a yearly minimum; Google Play required API 35 for new apps as of August 2025.
16 KB Page Size
Android 15+ requirement (November 2025) for apps targeting Android 15 and higher. Native libraries must support 16 KB memory pages.
Play App Signing
Google’s default-since-2020 signing service where Google holds your app signing key. Lets you rotate the upload key if compromised.
Upload Key
The Android keystore you generate and hold. You sign every AAB you upload to Play with it. Distinct from the app signing key.
App Signing Key
The key used to sign the final device-installed Android APK. With Play App Signing enabled, Google holds this key. Without, you hold both keys.
Distribution Certificate
The iOS certificate used to sign apps for App Store distribution. Issued by Apple, tied to your Developer Program membership.
Provisioning Profile
The iOS file that links your app’s bundle ID, signing certificate, entitlements, and authorized devices. Required for every iOS build.
Rejection & review
ITMS-91053 / 91056 / 91061
The three iOS submission error codes for Privacy Manifest violations — missing API declaration, invalid manifest, and missing framework manifest respectively. See the privacy manifest guide.
Guideline 2.1 (Apple)
App Completeness. The #1 rejection reason on iOS — app crashes, demo account broken, or incomplete functionality.
Guideline 4.3 (Apple)
Design: Spam. Rejection for apps that are duplicative, templated, or functionally too-thin. Subjective.
Guideline 5.1.1 (Apple)
Data Collection and Storage. Where Privacy Manifest, account deletion, and consent-gated data collection issues live.
Guideline 5.2 (Apple)
Intellectual Property. Trademark violations, competitor name usage in keywords, content-ownership issues. See the rejection reasons index.
Guideline 3.1.1 (Apple)
In-App Purchase. Rejection for bypassing StoreKit for digital content.
Beta App Review
Apple’s lightweight review for the first external TestFlight build of each version. Subsequent patch builds of the same version skip it.
Resolution Center
App Store Connect’s threaded interface where rejection letters and developer replies are exchanged. All history on a given app is preserved.
Deceptive Behavior (Play)
Google Play’s policy covering impersonation, copycat apps, misleading metadata, and fake functionality. Common post-launch pull reason.
Data Safety Mismatch (Play)
When your Play Data safety form doesn’t match what the app actually collects. See the recovery playbook for the reply pattern.
Testing
TestFlight
Apple’s iOS beta distribution platform. 100 internal testers, 10,000 external. 90-day build expiry. See TestFlight vs Play Internal Testing.
Internal Testing (Play)
Google Play’s fastest testing track — up to 100 testers, no Play review required, ~5 minute propagation.
Closed Testing (Play)
Google Play’s mid-tier testing track — up to 10,000+ testers via email list or Google Group. Requires Play review.
Open Testing (Play)
Google Play’s public beta track. Surfaces publicly on the listing with a “Join beta” button. Requires Play review.
SKStoreReviewController
Apple’s iOS API for prompting a user to rate the app. Respects a 3-per-365-day prompt cap automatically.
Play In-App Review API
Google’s Android equivalent of SKStoreReviewController — presents the native Play review prompt without leaving the app.
Keywords & ranking
Keyword Cluster
A small group (typically 3) of related, high-intent keywords you target across your title, subtitle, and keywords field.
Three-Keyword Rule
Pick three keywords you can realistically rank top-10 for in 90 days. Drop the rest. See the keyword research playbook.
Autocomplete
The ranked list of suggestions Apple or Google shows as you type in App Store / Play search. The highest-signal free keyword research data source.
Search Volume
Approximate number of monthly searches for a keyword. Directly observable only through paid tools; inferred from autocomplete prominence otherwise.
Keyword Difficulty
A rough score of how hard it is to rank for a keyword. Driven by competition strength, app quality in the top 10, and how many apps are targeting the term.
ASO vs SEO
ASO ranks apps inside the App Store and Google Play. SEO ranks websites on Google. Overlapping principles; different mechanics and character limits.
ASA (Apple Search Ads)
Apple’s cost-per-tap paid search channel for the App Store. Separate from organic ASO. See Apple Search Ads for indies.
Product Page Optimization (PPO)
Apple’s A/B testing system for iOS product page variants — up to 3 variants per dimension, live-traffic comparison. Requires a live app.
Post-launch
Developer Response
Your public reply to a user’s review. Shown inline on the product page as of 2024. See the review responses playbook.
App Privacy Label
Apple’s user-facing summary of your data collection, filled in App Store Connect. Must match the Privacy Manifest in the binary.
Data Safety Form (Play)
Google’s equivalent of the App Privacy label. Filled in Play Console. Uses different data categories than Apple.
Policy Violation
A breach of Apple or Google’s published rules. Triggers rejection pre-launch or removal post-launch.
Appeal Window (Play)
The 7-day window after a Google Play removal in which you can submit an appeal. Miss it and the removal becomes permanent.
Ranking Recovery
The process of returning to pre-incident search rankings after reinstatement, re-submission after rejection, or a major metadata change. Typically 2–8 weeks.
Store Listing Experiments
Google Play’s A/B testing system for listing assets — icon, screenshots, description variants. Plays the same role as Apple’s PPO.
Reader App Entitlement
Apple’s carve-out that lets certain apps (news, magazines, audio, books, video, cloud storage) link to external account management.
Metrics
Impressions
Number of times your app appeared in search results or featured sections. Visible in App Store Connect App Analytics and Google Play Console.
Product Page Views
Number of times users visited your product page after seeing an impression. Impressions → Product Page Views is your tap-through rate.
Install Rate / Conversion Rate
Percentage of product page visitors who install. Stores weight this signal heavily for ranking.
D1 / D7 Retention
Percentage of users who open the app 1 day and 7 days after install. A ranking signal on both stores.
CPI (Cost Per Install)
The average amount you pay to acquire one install through a paid channel. For ASA, typically $1–$20 depending on category.
LTV (Lifetime Value)
Total revenue generated from one user over their lifetime with your app. Needs to exceed CPI by at least 2x for paid acquisition to make sense.
Tap-Through Rate (TTR)
Impressions → Product Page Views expressed as a percentage. 15% or higher is a healthy indie benchmark.
Conversion Rate (CR)
Product Page Views → Installs as a percentage. 30% or higher is healthy for indie apps.
Apply the vocabulary with the tools that match it
Push My App ships every category in this glossary as a product surface: AI metadata generator, Screenshot Resizer, 14-language translator, Pre-Flight Scanner, and direct submission to both stores. The free keyword character counter, subtitle helper, screenshot size guide, and app icon resizer cover the free tier. Pair with the free ASO pre-submission checklist before you submit. See pricing for what is included in each plan.
Frequently asked questions
Is this glossary meant to be read from start to finish?
No. It's a reference. Use Ctrl-F to find the term you encountered, read the one-sentence definition, and click through to the deeper post if you want the full context. Most indies dip into this page many times over a product's first year, rather than reading it once.
How often is this glossary updated?
Whenever Apple or Google introduces a new term or deprecates an old one. Privacy Manifest was added in 2024. Liquid Glass icon variants were added in 2025. 16 KB page size requirement in 2025. If you're returning after 6 months away from App Store submission, re-scan this glossary for new entries.
Why no alphabetical index?
Grouping by category is more useful for indie developers than A-to-Z ordering. You usually arrive needing to understand a specific area (metadata, submission, rejections), not a specific letter. That said, Ctrl-F on this page finds any term instantly.
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