Easy Dice is an RPG dice rolling app featuring the following:

Variety of die types: D2, D4, D6, D8, D10, D10x10, D12, D20, D30
Choose which dice to roll together. For example a D4 with two D8.
Re-rolling of dice. Tap dice to select which ones will roll and which ones will stay.
Adding up: Sums all the die face values.
Die sets: keep die sets for later.
No special permissions required.

Adding the 2 sided die.