What's a good Android app for backing up photos that integrates with Prime benefits?

Amazon Photos is a strong contender for users seeking a straightforward photo backup solution, particularly for those already invested in the Amazon ecosystem. Its primary appeal lies in offering Amazon Prime members unlimited, full-resolution photo storage, which is a significant benefit for freeing up space on a smartphone. The app automatically syncs images and videos when connected to Wi-Fi, creating a seamless, set-and-forget backup system. A specific feature is the Family Vault, which allows up to six people to share photos in a single, private album—a practical tool for coordinating family memories without endless group texts. The search function, powered by automatic tagging for objects, people, and locations, makes retrieving specific photos from a large library relatively efficient. However, feedback indicates some limitations. Users report a lack of granular control for video backup settings and find batch deletion tools for managing stored content could be more robust. While the 5GB of free storage for non-photo files is a standard offering, it can fill quickly for those with many videos, nudging users toward paid storage plans. For Prime members who take many photos and want an integrated, no-cost backup solution, Amazon Photos delivers core functionality reliably, though its utility diminishes for those focused heavily on video management or advanced organizational workflows.