CPT is software for testing (among other things) one's opening repertoire knowledge.
I'm wondering if there are any other similar pieces of software I should consider.
I like the online chesstempo beta opening manager and trainer. I have read on the facebook page of chess position trainer, that chess position trainer 6 is coming this year. I aspect a lot from this software.
Lucas Chess has some interesting repertoire making functions. Like importing best moves or all best moves from a bin book, for one collar. You can export the openings to pgn but I have noticed that there is an error and there are many threefold and more-fold repetitions in the games. You can solve this by importing the pgn in chess position trainer and export to pgn again. I also like Hiarcs Chess explorer. You can sort games for one player by opening name. So you can make repertoires for it. You can edit the player name in a text editor or in Chess Assistant.
Bookup/Chess Openings Wizard, Chess Opening Trainer (which had a PC version too) and Chess Position Trainer are some of the main options, but just for completeness sake:
Chessbase lets you add 'training annotation' to moves in a game, so when you switch on training, it will hide the continuation, and quiz you.
Lucas Chess now lets you set up a Personal Opening Guide, and then test it via Learn Tactics by repetition.
SCID has a 'find best move' feature.
Heuristic Opening Repertoire Specialist & Trainer (H.O.R.S.T.) allows you to "train variations by using a training assistant."
Jan Kaan's Bookbuilder has a "book training module."