I have Roy Dean's blue and purple requirements app but am looking to add more. What are you guys using, if anything?
I just picked up Roli Delgado's ibjjf legal leg locks and this it's really good; and it's really niche as their hasn't been a product like it to my knowledge 
I have loads!
The Kid Peligro ones are all good - plenty of detail for improving your core basics.
Same goes for the Stephan Kesting stuff.
My favourite is probably either Leticia Ribeiro's X guard app or Lovato's Omoplata - both of these give loads of stuff on a particular aspect of jiu jitsu.
BJJ dice and Round Timer Free are both essentials too - I use the latter all the time.
I would love to get some of Kid Peligros stuff but I think he is on apple only, no?
did roli's app ever hit android?
Love the different format of iBJJ
FatFrenchFry - Love the different format of iBJJAnyone else use this who had purchased the wrestling module?
It's now vanished from the app!!!
Kid Ps apps are good I have two of them and one for Portuguese. I like his style of teaching.
Xande Ribeiro's passing the guard, Caio Terra's modern jj series, Kid Peligro's apps, and some of Kesting's stuff (instant gamechangers etc).
Also, the ibjjf legal leglocks app someone mentioned earlier. 
Samuel Bragas Berimbolo app, Dave Camarillo, Kesting, Orlando Sanchez', fighting films judo app.