As an Ulthwe player I was a big fan of the old GW psychic app, which helped me keep track of my psychic powers. Once 7th launched they killed the app, changed and expanded the powers, so the old app doesn't really assist all that much.
That being the case I've created a handy sheet to help me for larger games. I have a draft of the Farseer one in progress, but this is the Warlock/Spiritseer sheet. It's a sheet with pictures of all my models with check boxes and I laminated the page so that I can use it over and over again.
All in all it should make book keeping during a game that much quicker, and speed up my game. Feel free to use this idea to make your own.