You should try the Capture app by Soundtrap. It basically has exactly that functionality you describe. It's quite limited beyond that, IMHO, but give it a go and let me know what you think.
Looping for my use case can be as simple as a toggle button (even in a hamburger menu somewhere :). I also know the challenges of looping mp3s seamlessly and am only thinking of wavs.
Cheers!
- Capture: Import was super easy but I see no way to loop, so that's out. - Studio: Full-blown collaborative DAW (overkill) but importing your own loops is gone (wtf?!).
Looks like I'll wait for you guys to hopefully add importing audio files and looping.
If you sign up to our email newsletter on our website, you will also hear from us when the feature is out. There will likely be a few emails before that I'm afraid, as we have a few other features in the pipeline worth communicating, but I promise that we'll treat your inbox with respect.