Deleted

Neither.
Over time, achievements really lose their "worth" and impact they have on the gameplay / replayability. It is different from game to game, but more often than it used to be the case I play the game and not the "achievement-game".

it not only shows you what games you 100% achievements for

it shows far more then that if you login and sync your achievements.. it will tell you the exact amount of % (if it's freshly synced) as well as gives you details on how to do certain achievements if someone has made a tutorial for it (user edited).

edit: oops, you said "not only" sorry.. i thought it said "it only shows". xD my bad

https://completionist.me/ try this instead