I built a simple 3D dice roller to roll dice with your friends (or foes, not judging.) No signup or download, simply tap "Roll Dice" to roll together with your party :
3D Printed Foldable Dice Tower Collapsible With Tray Dungeons and Dragons DND Dice Roller Gaming Accessory Fold Down Castle 3D Dice Tower - Etsy Sweden
DnDice - 3D RPG Dice Roller:Amazon.com:Appstore for Android
DiceBox RPG brings true 3D RPG dice rolling to Windows Phone 7 - MSPoweruser