I throughly tested this app, and the companion desktop app, with two photo shots (two rolls of film), and overall, it works fairly well. There are some important fixes/changes needed to make both right.
First, the iOS app itself works well, and it seems like prior reviewer's issues have been addressed.
Suggestions: (1) Need a way to read the shutter speeds in between the numbered markers. (2) There are three ranges of standard apertures, but they are not listed out - and they seem to be associated with the camera, not the lens.
Second, the free Mac OS desktop app works, but crashes consistently upon completion of writing the metadata to your scanned files. And by "crashes", I mean it really crashes hard, the desktop slows to a crawl, and it's very difficult to 'force quit' it to get your system back to normal. It does work, however, and upon completion the metadata (time, date, camera, location, etc.) is all there. And, the scanned TIFF files are intact and not corrupted.
Finally, the metadata written to the digital image files shows the 'camera' brand as the 'scanner' brand (original data from the scanning process).
Suggestions: (1) An option to choose what metadata gets written to the file, as typically the scanner and scanning software information is written first. (2) A countdown bar indicating the number of files being processed. (3) No crashing, obviously.
I stumbled upon the ability to select which numbered metadata can be saved to which actual image, which is nice. This is important if you accidentally have more data in the app than you do actual pictures.
The documentation is almost non-existent, except for the fancy website, which looks nice but does not have enough practical information. I learned the iOS and desktop apps all though trial-and-error.
Please fix these small issues with is iOS app, and fix small issues and big crash with the Mac OS app!