Fantastic. Dirt simple to use, with a great deal of accessible depth that's totally optional.  Rolling can be as easy as tapping your phone screen or have the tactile pleasure of 'shaking' the die or dice around before flinging them across the digital table. Handles math for you, simple stuff like "sum all this" to more complicated stuff like "Best 2 of 5, 5s and 6s explode". Happy to fudge non-existing dice (1d17, for instance). Highly adjustable if you drill down into it - custom colors are just the beginning.

Great stuff. I adore it.