Most of the time I play skirmish only for lots of reasons. But one of my main reasons is, how unreliable my fellow players are, or unwilling to commit themselves to a "regular" campaign night. Some of them are more casual gamers, that really want to play this game, but not on a regular basis.
Therefore, I'd really love to see another game mode with just single missions. Pick a character and don't worry about leveling up, a next game night or whatever. The first mission of LotA does just that, the X-Com board game does that perfectly. I'd love to see that in the App ...