I think basically having the ability to have preset rolls. So if you make a lot of characters you can have a roll set called "Character - D&D 5e" and it will automatically roll 4d6 six times for you.
A bonus would be to have the ability as a GM to set up rolls pregame, so that a player can hit "generate character" and have all of the rolls done for them.
Example: My Dungeon Crawl Classics game has a lot of pre-rolling (lots of rolls per character, four characters)
Quote:
Stats - 3d6, 3d6, 3d6, 3d6, 3d6, 3d6
Luck score - 1d30
Occupation - 1d100
Starting copper - 5d12
Extra starting equipment - 1d24
Hit points - 1d4
Might be nice to be able to set that as a game preset and have the players just hit a button to make it happen.