This is Pro Tuner Lite - Chromatic Tuner, a tuner app released for iOS on Aug 11, 2011. It is unknown when this was delisted exactly, the app was originally downloaded on my account on January 9, 2014, and a Wayback page indicated it did not exist as of November 27, 2020, so it was sometime between those 2 dates. This is a 32 bit only app, so it will only work on iOS 10 or lower.
