This app allows any DnD player to quickly roll up a variety of character stat sets. You can pick your class and your roll set(for example, 4d6 and drop the worst roll). It then rolls 6 stats for your character. These stats are assigned in the normal order for your class. If you want to make unusual builds such as Strength-based Ranger you will have to switch your stats around afterwards.
This app also remembers the previous character roll sets that you have rolled. You can roll multiple characters in a row and then look through the history to see what they were.