Does it have to be a mobile app? Id love to do this when im bored at work but i dont wanna make it seem like im just sitting on my phone.
A web app would also make it work on iOS (and other non-Android platforms) at the same time
Rapid Editor is a good web app for editing OSM: https://rapideditor.org/
You can edit OSM from its main site [0], although there's a much steeper learning curve when using the site (as you have far more freedom and it's not super easy to figure out the standard way to tag some situations).
You can edit OSM from their web apps. This is intended to be used in the field but I guess you could use it to find things that need fixing.
I think the reasoning behind this is that ideally you're at the location where you can confirm what you see, instead of maybe referring to older media or from memory.
That being said, I agree with you and would like to see more ways to access the tool!