Most BJJ apps let you log a session and that's it. You end up with a list of dates and a number — but no real picture of where you stand.
A real tracker should answer one question: are you on track for your next belt? That requires connecting your sessions to the IBJJF graduation system, weighting volume vs consistency vs time in grade, and showing you the gap.
BJJ Belt Progress is built around exactly that. Every session you log feeds into your BJJ Index, which is recalculated against IBJJF requirements in real time.