Jalmyr II is th mission pack. Be careful with in-app purchases. Pack was purchased fine but app crashed and then wouldn't let me start the app and login again until I deleted the app and installed again.
Soon this is going to a a fine iPad game! Can't wait.
I've run into some weird bugs on my iPad Pro as well, but nothing quite as bad as what you are mentioning. I've heard similar with other Air owners. For me the app goes unresponsive at times until a force restart. I've heard they are working on all this stuff and agree it'll be solid at some point on iPad. The game is fun, which is the bigger deal.
My theory is they rushed it a bit to beat Elder Scrolls (3/23) to the punch. That's absolutely valid because I'm trying to figure out how to possibly try both concurrently!