Topic: Serving static files that could change over time

Hi guys

My application uses Twilio and thus requires a couple of mp3 files to be played to the caller, and I'm wondering how I could easily (for me as a developer) let my lient (the admin of the app) upload new mp3 files easily as well (for them).

The app will most likely be hosted on Heroku so FTP is out of the question...

Any ideas?
Thank you!