I don't usually leave posts like this, but I am appreciative on what your trying to do. Also game development can be pretty hard.
There is a big lag when returning to the vault on android as it tries to load the vault. Its very similar to how old android devices use to shift to different scenes and it isn't seemless. There is also a lag when clicking on any of the section in the vault. I also found some cases were russian text is still left like with the cat on English mode.