Game Lab commands don't necessarily work in App Lab, as you've noted. There's of course similar structures like loops, functions, and variables, but a lot of the environment specific tools wouldn't translate well. If you want you can check out some of the canvas drawing in App Lab but my feeling is if kids really want to do animations then CSD is a more purpose-built tool for that.
One solution is just have students work in studio.code.org/s/csd3 and you can track their progress through the unit that teaches Game Lab. Especially if they have some programming experience under their belt there will be parts of that unit that they'll be able to progress through quickly. Note, however, that the central paradigms of the two tools are really different. In App Lab you're usually thinking about events. In Game Lab you'll be working with a constantly running "draw loop" that pushes forward the animation. Just something to keep an eye on.
You can coerce App Lab into doing animations using the timedLoop() block but in general you'll just not have the same set of tools designed around animation unless you go over to Game Lab.
Hope that helps!