Hi all, I'm Dmitrii. I'm building ScoreLens, an iPhone app that reads a single-part PDF (or a photo of a printed part) and plays it back with a cursor, so you can hear a passage slowly or at concert pitch before rehearsal.
I've been testing it on IMSLP parts and would like help finding where it fails. What it handles: one melody per staff (orchestral and band parts, vocal lines, études). What it doesn't: piano scores, handwriting. Older scans with faint staff lines are the hardest.
If you try a part and it misreads something, a link to the IMSLP file and the bar number would help a lot. The app is free to try: https://scorelens.app
Disclosure: I'm the developer.