2 years ago, I put online jststrt, a small app providing a minimal habit tracker. It's available for free on the web browser and it is aimed helping people to form habits and hopefully getting better.
As of may 2019, more than 2000 people signed up and hundreds tracked stuff regularly. Some nice people even took the time to write me and say "thank you".
Running costs of the platform are around 10€ per month. If it helped you in any way or just found it useful, please consider buy me a coffee :)