It's free for open source work, and you can sign up as a student if you're still in school to get it for free for a while.

But yeah, I pay for it now because it's such a significant time saver for my day-to-day. I'm always aware of what my coworkers are doing because it auto-fetches every minute. I use it for code review as well, because I find it really easy and snappy to navigate file changes in a commit (I always use split view, and I almost always have "hide whitespaces changes" on). I has a great interface for interactive rebases as well, allowing to drag to reorder commits, etc. Good built-in merge conflict resolution tool.