Hi there,
I made very easy Excel sheet to track progress of my heroes, as the in-game roster is not clear enough for me. Decided to share it with You.
https://drive.google.com/file/d/0BxG3kU … sp=sharing (open in new window, then save using Ctrl + S)
How it works?
CHAR - all the characters in alphabetical order
available - max level You can level Your hero with the covers You have
current - current level of Your hero
stars - the rarity of the character
maxed - max level hero can achieve with all their covers available
build - either Your current build or in case of leveling in progress - Your target build
covers - max amount of covers for this hero
covers owned - covers You already own for this hero
At the bottom You get the TOTAL sum of either levels and covers (it sums automatically).
Colors? Why colors?
Black - hero You own, not maxed covers and levels
Purple - hero You have zero covers for
Blue - hero with maxed covers but not maxed levels
Red - hero with both maxed covers and levels
other possible colors:
Green - hero whose leveling is a priority to You
Turquoise - hero You want to respec
Hope it will help somebody 
Comments more than welcome.