Have you ever felt that a Critical Hit should be a little more epic that just more damage?
That a Fumble should be something more that just a miss?

CriticalRoll is what you looked for. It is a simple app that adds unexpected effects in combats, to create interesting scenarios and improve the story's narrative.

It designed for systems like Pathfinder and D&D, but it can be easily adapted to another similar systems

Some Critical effects can be devastating against playable characters, therefore it's suggested to reserve those effects for villains or main NPCs
Similarly, Fumbles effects can cripple a character seriously, so be sure that everyone agrees in using them.

This App is inspired on iCrit and iFumble from Paizo, which are based on their Gamemastery Critical Hit and Gamemastery Critical Fumble Decks.
Be sure to check them out and see if they meet your needs.

CriticalRoll is not endorsed by Paizo Publishing, LLC. or Wizards of the Coast, Inc. We love their work and just wanted to make a tool to improve the game.

This is an open source app. It is free and doesn't have any Ads.
If you want to contribute to this app, you can check the repository:
https://github.com/gemorelli/CriticalRoll

Feel free to make any suggestion or report any issue!

Have fun!