There is a very minimal one I made in a few hours for my own use. Select characters, select the CR, hit "award". For each character, it will figure out XP from the table, divide it by the number of characters selected, and add it to that character's total. The rest is easy. It also saves the XP of every character, and it can handle multiple campaigns.
The only "nifty feature" it has is the ability to drop a character one level in such a way that it has proportionally the same relative amount of XP to the next level (eg, if you lose a level when you're 90% of the way to 14th, it'll put you at 90% of the way to 13th). I never quite understood what's the official way of dropping a level, but this sounds fair to me.