This app was mentioned in 2 comments, with an average of 1.00 upvote
We were doing this before riot added those api features... although now we are using their API... check it out:
http://i.imgur.com/wrHgTBP.png
Just search on the android play store for "lol team strategy" or go here:
https://play.google.com/store/apps/details?id=com.adwave.lol.teamstrategy&hl=en
I like the button feature he has though. We added a "chance to win" based on how well each player is with their champion. Any feedback is welcome :)
A friend and I made an Android App Using Riots API that uses the same Info. It's a work in progress and any feedback would be Awesome