Looking for a Sleep Calculator replacement

Hello,

For the past couple years I've been using Sleep Calculator (https://play.google.com/store/apps/details?id=com.dealwatch24.sleepcalculator), but due it lacking any data export feature, all that data I've collected is unfortunately pretty much useless.

So I'm looking for a replacement which has these features:

• Tracks when I fall asleep and wake up
• Has a "sleep notes" feature which lets me apply user-defined tags for each day (whether I drank coffee that day, exercised, was sick, etc.)
• Can export data to CSV or other format
• Has an alarm (though this isn't strictly necessary to have)
• Open source (preferably)

I don't care about any other features. If it has the above features, it would be better than what I'm using now.

Thanks!