Maybe you've discussed this before somewhere but… The name suggests two things that I think hinder the service:
- This is a service for software developers only (git)
- A tip is a small amount of money in exchange for quality service
There is no reason to tie yourself only to software developers. There are a lot of other places where people may want to show appreciation for each other in an open way.
There is also no reason to associate yourself with tipping culture. Tipping causes many people anxiety and has power dynamics and cultural norms attached to it. Tips are supposed to be small and in exchange for service.
I really think a more abstract name would allow people to connect with it better.
Good luck with year three!