Over the weekend, Roll20 announced their Mobile App. At the moment, it only works with Dungeons & Dragons 5e, but other rulesets/character sheets are apparently in the works.
Available for Android and iOS
Roll20 Player Companion
Your characters. Your friends. Your table.
Take your Roll20 characters with you, wherever you go. Keep your character in your back pocket at the game store or your living room! Reference and make rolls on your TTRPG character sheet from your phone or tablet.
* Free for all Roll20 users!
* Swipe and tap to select your games and character sheets.
* View your character’s stats, skills, features, and proficiencies.
* Roll for skill checks, combat, and spells (don’t worry, Roll20 will do the math for you).
* The sheet displays your character’s important information including their armor class, HP, speed, and character portrait.
* Send all your rolls right to the VTT chat, powered by Roll20’s signature quantum roll server.