For each level? Cuz I'm using them as much as possible, and they aren't leveling up!
To get from level 1 to level 2 you have to use the power 15 times. To get from level 2 to level 3 you have to use the(level 2) power 30 times. It appears using the level one power does NOT level up to level 3 - once you've reached level 2, you have to use level 2 to progress. copied everything from here
hope I helped:)