We're running a few candy crush tournaments for this exhibition (thematically linked) and I would really like to emulate (visually not literally) a mobile screen/project in 3:4 but I'm not sure it's possible without just using actual phones...
I actually might just literally set up some cardboard filters/frames for this instead..
@jenkshields Honestly the lowest cost approach might be to use bluestacks on a laptop and plug that to a projector or a normal display tilted at 90". Add some cardboard bezel and you can have a "big android phone".
The projector / screen still costs but those should be easier to find for PCs than smartphone oriented stuff. 
@polychrome yeah, I did think about bluestacks! We've got the projectors already so it'd definitely be the simplest option I think.
I know it's possible to use adapters for both android and ios but we don't have budget and because it's a public event & the tournament is a time trial thing I'd be wary of it not working so well