The Android build of AIPPics, downloaded straight from this site. It is a separate app from any other build of AIPPics (its own data), signed with AISKSoft's own key.
Checking the latest version…
Nothing updates this app automatically: when a newer version is published, AIPPics tells you at launch and opens the download page; install it over the old one and your data stays.
Compare the file's sha256 with the one above (shasum -a 256 <file> on a computer). The app is signed with a key whose certificate has this SHA-256 fingerprint — apksigner verify --print-certs shows it:
88:7D:AA:4B:24:FE:7D:18:A5:85:78:7E:28:36:E4:18:E1:DF:6A:C0:F8:B5:42:C4:90:5B:D8:D5:9A:00:E5:53