This app was mentioned in 8 comments, with an average of 19.38 upvotes
I used Google Lens and found out it’s an android app called HumOn https://play.google.com/store/apps/details?id=com.musicroquis.hum_on&hl=en_US&gl=US
Try this. It exists for iPhone too.
HumOn on Android, if that's your thing.
Hum On! is the closest equivalent but it's not up to Music Memos standards.