The app is for Android and can be found here.
A post on Reddit explains:
“It’s not done yet but I wanted to let you guys know about it to get some feedback on what I should change, improve, or add. There’s a Lite (free) and a Full (paid) version, but you can check out all the features in the Lite version.”
The app actually looks pretty cool with what it can do. Basics include:
multiple characters (Lite is limited to 1)
show class / advanced class abilities
make multiple skill tree builds (Lite is limited to 1)
customize the interface to show/hide stuff you don’t care about
And there are some unique things that it can do as well. The creator says he is really into details so he created the app to be specific to the details. Other things it can do are:
keeps track of the order of points assigned in your skill tree build
you can change your character’s level and it will highlight abilities available to that level (class abilities, AC abilities, and skill tree abilities)
when you look at an ability, it will show you passive modifications from your skill tree build (and whether they’re available to your character at its current level)
If you check it out for yourself, be sure to drop in and let us know what you think.