The app is closed source and apparently full of trackers, which is a deal breaker for me.

Edit: But thank you for the suggestion!

Thank you! Been sober for a month and my body already feels so much healthier!

Hehe, I also considered to start an open source project prior to asking the question. :p

However, I found that Sobriety is working fine for my use case. Will definitely try to contribute to that project in the future!