This app was mentioned in 2 comments, with an average of 2.50 upvotes
http://tabletopaudio.com/
I also recommend https://play.google.com/store/apps/details?id=com.dragaoboreal.songsanddragons&hl=en for your android tablet/phone
https://play.google.com/store/apps/details?id=com.dragaoboreal.songsanddragons&hl=en