A web application that shows your next Battlefield 4 weapon attachment unlocks.
Try out the tool here: https://bf4-next-unlocks.vercel.app
Because BF4's own suggestions for next unlocks seem to be suggested by % completed instead of the absolute amount of kills. This means that an unlock where you need 50 kills is suggested before an unlock where you need 1 kill.
BF4DB or some other stat service used to show these stats, but not anymore.