I think one of the best things you can do in the app (when we have enough meta knowledge about the game) is which stones work best with which characters.
In the Stone information menu, you should always have a list of characters that work well with that stone. That is very useful information for new players. I am sure we are going to get a lot of questions like "I like X and Y characters but don't know which stone to use with the?"
There could also be a section on commonly used teams with a brief explanation of why they work, pros and cons.
At the same time, in each character's section you should have best pairings and stones for that individual character. These can and should be more than one so people can mix and match as they see fit.
Example:
When you click on Strider, it should have all the relevant information on him (frame data, how to use his moves, his game plan, his role on a team, sample combos) and then it should have his best partners and stones.
Best Partners (this is hypothetical don't copy this stuff):
Dr Strange
Arthur
Iron Man
Megaman X
Ultron
Best Stones (in order):
Power
Reality
Mind