So quite a while back I noticed nearly all of the campaign mission pages were missing video walkthroughs.
Well, I finally found a working screen capture app for my GS4. It's not perfect- resolution could be better, framerates a bit faster, and since audio can only be recorded through the mic audio doesn't sound as good as it does normally (though definitely usable).
Here's a quick demo. Still trying to find optimal settings, so the actual mission walkthroughs will be all around better. http://youtu.be/76ZIzobP9rs
Let me know if that is good enough and I'll start going through MC3 and MC4 campaigns (MCS/MC2 not compatible).