Update your app regularly to add new features and increase your chances of being featured.
Apple - you can only update your app name & listing every time you release an update.
Apple Promotional Text Field
> The keywords used in the promotional text will not rank your app in the search results.
> Appears above the long description in the app page.
> Good for highlighting promos, new features, and other new content.
> Apple Character Limit: 170
"What's New" Field
> Keywords in this section won't help ranking.
> Use the field for new features and updates.
> Try to tell a story about new features and improvements.
> Ask for feedback and reviews.
Optimize your Developer/Seller Name
> More visible in Google Play as it shows in search results.
> Keywords in the developer/seller name do rank, providing an opportunity to increase your app’s visibility on your main keywords.
> Optimize your package name before launching a new app too, especially for Android. I believe keywords in your APK package name help your ranking.
> Use Firebase Crashlytics to track crashes & fix bugs in a timely minor for high impact issues.
> Google for sure tracks app stability, consistent poor performance will result in lower rankings.
> Retention is very important for your ASO and would require much more detail but here are a few simple tips.
> Add a push notification feature - either local reminders or remote cloud notifications to remind a user to use the app.
> Provide a welcome / onboarding flow in your app to explain the app to people and help them complete a task in the app.
> Continue to listen to user feedback and tweak the app to retain current users and improve the experience for future users.