You can take still shots and video with MSQRD, and you don't have to have actual people around to use it on—MSQRD works just as well with photos of people. The app is also able to adapt to your facial expression, so closing your eyes, tilting your head, or opening your mouth will change the "mask" accordingly.
Once you're done, you can share your picture or video to Facebook, Twitter, or Instagram, and it'll be available in your gallery app as well.
There aren't a ton of masks available at present, but look for them to grow and for a "mask store" to be implemented as the app progresses through beta. And sadly, after a short investigation, MSQRD does not appear to work on cats. Oh well... can't have it all.