Valid concern I suppose. Although I think that if Crypto gets big enough to cause the US government to take such a huge action against mobile companies. Those companies will fight it tooth and nail. They wouldn't want to lose their consumers.

There will always to other ways to run and install apps as well, it may pose challenges to the non-technical folk but people will build solutions.

On the bright side it could potentially have the effect of giving a large boost of users to Open Sourced mobile platforms.