A couple of days ago I stumbled upon an official LEGO Movie Maker app from TLG on the ios app store. It's been out for over a year so everyone might already know about it
I'm sure there's plenty of stop-motion apps out there but it's nice to have an official LEGO one. It's nothing fancy, there's just a couple of very basic effects and onion skinning. But it's free so why not? I guess this is the evolution of the old Studios software. I had a lot of fun with that back in the day so it's nice to see TLG are still supporting brickfilms.
I used the app on my phone to make this terrible little test video:
There is a little bit of post production in there but you get the idea