Tabby is a tool I made for myself due to lack of practical and unannoying tools to manage debt and remind people about it. Since existing solutions require accounts for people to even see how much you owe, or have other annoying requirements or missing features, I created Tabby with the idea that it would serve all of my needs and be as enjoyable for my debtors as possible (I was mostly just tired of reminding people to pay back their meals). While initially developing Tabby as mostly a quick little script, I somehow managed to develop it in full. So since it works surprisingly well and has a bunch of features, I ended up FOSSing it. It's something I very much believe in ideologically, and I think it might be useful to others. From time to time, I still add new features to Tabby to make it more convenient for me or if a friend (or a user on GitHub) requests a specific feature that also makes sense to me.