App Store Screenshot & ASO Glossary

Plain-English definitions of App Store and Google Play listing terms: custom product pages, PPO, app previews, feature graphic, alpha channel, display classes and more.

• App Store Optimization (ASO) App Store Optimization (ASO) is improving an app’s store listing so more people find it and install it: name, subtitle, keywords, screenshots and previews.
• Custom product page Custom product pages are extra versions of your App Store page with different screenshots, previews and promotional text. Apple allows up to 70.
• Product page optimization (PPO) Product page optimization (PPO) A/B tests up to 3 alternate icons, screenshot sets and previews on your App Store page for up to 90 days.
• App preview An app preview is a 15–30 second video on your App Store page. Up to 3 per size and language, screen captures of the app only, 886 × 1920 for the 6.9-inch iPhone.
• Feature graphic The feature graphic is the required 1024 × 500 banner on a Google Play listing, used as a video cover and in large-format collections.
• Promotional text Promotional text is the 170-character line above your App Store description that you can change any time without submitting an update.
• App subtitle The App Store subtitle is a 30-character summary under your app’s name. What to put in it, and how it relates to screenshot captions.
• Keywords field The App Store keywords field takes up to 100 bytes of comma-separated keywords. Why bytes matter for non-English locales and what not to include.
• Alpha channel An alpha channel stores transparency in an image. App Store Connect and Google Play reject screenshots that have one, even if every pixel is opaque.
• Device frame A device frame is the image of a phone, tablet or computer drawn around a screenshot. How frames fit screenshots, and when to use none.
• Mockup An app mockup is a realistic image of your app on a device, used in store screenshots, websites and press kits. Types and when to use each.
• Panoramic screenshots Panoramic screenshots share one continuous background across neighbouring screens so the row reads as one image. How they work and when to use them.
• Screenshot caption A screenshot caption (headline) is the short text on a store screenshot. How long it should be, what to say, and what each store forbids.
• Store listing experiment Store listing experiments are Google Play’s A/B tests for listing graphics and text. How they compare with Apple’s product page optimization.
• Short description (Google Play) The Google Play short description is the 80-character summary users see first on your listing. Rules, examples and how it works with screenshots.
• Display class (screenshot size group) App Store Connect groups devices into display classes, each accepting certain screenshot sizes. How the groups and fallbacks work in 2026.
• Dynamic Island Apple names its two main iPhone screenshot groups after the Dynamic Island: large (6.9-inch, 1320 × 2868) and medium (6.3-inch, 1206 × 2622).
• Status bar override (9:41) A status bar override sets a clean time, full battery and signal before you capture screenshots. Commands for the iOS Simulator and Android.
• Locale code Locale codes identify a language (and sometimes region) for store metadata, such as de-DE or zh-Hans. Apple and Google use different codes for some languages.
• Right-to-left (RTL) screenshots RTL screenshots are store screenshots for right-to-left languages such as Arabic, Hebrew and Urdu: mirrored layout, right-aligned captions and RTL app UI.
• App icon (store) Google Play needs a 512 × 512 px, 32-bit PNG store icon up to 1024 KB. How store icons differ from launcher icons and screenshots.
• What’s New text “What’s New” describes changes in a version, up to 4000 characters. Guideline 2.3.12 requires significant changes to be listed.