A geotagging app for cats, idea and UX/UI from Winnie Gong!
Status: Currently in extreme "alpha" stage, as I'm setting up some back end work (planning to learn Django for this, since, while it's a new tech for me, it also is written in Python so I'm at least somewhat familiar with it). Front end code is on Github.
A mobile app (Android only at the moment) where you can plug in your music and, using a heart rate monitor (Bluetooth Low Energy), get feedback from your workout just by listening to your songs! If your heart rate is lower than it should be, you'll hear your song slow down; if it's too high though, that song will be too fast too!
Status: Available on Bitbucket repo, still has some (reported) bugs that I haven't been able to reproduce. Would like to find a way to use streaming audio so I wouldn't have to load MP3 files on my phone though!