GALLERY_ADD_ONLY

Permission to save media into the photo library, without the ability to read it.

Use this for a camera app that stores its own captures, a scanner that exports a document, or anything else that only ever writes. Asking for full read/write access to satisfy a save-only feature is over-asking: it is a larger privacy ask, is denied more often, and invites an App Store review question about why the library is being read.

• Android: no permission at all on API 29+ — MediaStore inserts into the app's own collections under scoped storage — so this reports GrantStatus.GRANTED without a prompt. On API 26-28 it maps to WRITE_EXTERNAL_STORAGE.

• iOS: PHAccessLevelAddOnly, declared with NSPhotoLibraryAddUsageDescription. Add-only never returns "Limited", so GrantStatus.PARTIAL_GRANTED is not reachable here.