Cairn

Cairn lines up each new photo with the previous one, so a series taken over weeks or months actually looks like the same shot. The app aligns camera framing. It does not diagnose anything, measure treatment outcomes, or provide medical advice. Open the camera and a transparent copy of your last photo appears over the live view. Match the edges, take the shot, and it joins the project's timeline. That is the whole idea: the framing stays put, so the change is the only thing that moves. WHAT IT IS FOR A plant on the windowsill. A room mid-renovation. A beard growing out. A wall being tiled. Anything that changes too slowly to notice day to day, but unmistakably between the first photo and the fortieth. SEE THE CHANGE Compare any two dates side by side, with a slider, or as a fade. Export a still, an animation, or a video and the alignment holds all the way through. STAY ON SCHEDULE Set a reminder per project — daily, weekly, every two weeks, or monthly — so the series does not quietly stop after week three. PRIVATE BY DESIGN No account. No ads. No cloud upload. Your photos stay on your device, and the app works with no network connection at all. FREE Two active projects, the ghost overlay, alignment grid, side-by-side, slider and fade comparison, and standard image exports. CAIRN PRO — ONE PURCHASE, NOT A SUBSCRIPTION Unlimited active projects. Timelapse video, home screen widgets, and the edge overlay during capture. 4K exports, PDF reports, GIFs, and custom reminder intervals.