As long as the app is already installed, you should be fine.  Or, whenever you're able to reinstall it you can restore your backup.  Personally, I don't trust any single wallet.  I generate a private key using MultiBit, save it on a flash drive or paper, and import it into Mycelium.  That way I have access to the same wallet on my PC and my phone.  You just need to make extra sure that your PC is clean.