Twinkeep finds duplicate photos, videos, music and documents on your Mac by their content, not their filename, and groups lookalike photos for side-by-side review. Nothing is deleted outright: every removal goes to Quarantine and can be restored. File Rules watch folders like Downloads and file new arrivals automatically. Plus Compress, Junk Sweep and Disk Analysis to win back space. Runs offline, no account. $9.99 once, no subscription.