Rejected? Start here.

The rejections developers search for most, and the checks that catch them before the reviewer does.

• Rejected under Apple 5.1.1: data collection and storage
  The most common rejection. Apple's reviewer could not see why the app collects what it collects, or the app asked before it explained.
• Google Play refused the background location declaration
  Play wants one core feature, a prominent in-app disclosure, the same words in the listing, a video, and the form. Miss one and the whole declaration is refused.
• Google Play: target API level too low
  Every August the bar moves. An update below the required level is refused outright; an extension exists but must be requested before the deadline.
• Rejected under Apple 2.1: the reviewer could not sign in
  An app with a login needs a demo account that works on the day of review, in the review notes, with anything else the reviewer needs.
• Play's Data safety form does not match the app
  The form must match what the app and its SDKs actually collect. Play checks SDK manifests against it and rejects the mismatch.
• Apple: missing privacy manifest or required-reason API
  Every listed third-party SDK must ship a privacy manifest and the app's manifest must declare its data types and reasons.
• Rejected under Apple 4.2: minimum functionality
  A web page in a shell, or an app that does too little, is refused. Native features and a real use are what the reviewer looks for.