Feature Request: Splash Screen

[philipqueen]

Would it be possible to add a simple splash screen/loading screen to PyApp?

I'm using PyApp for a relatively large project, so it has to download ~3gb. On my Mac (not sure about Windows and Linux), the only visual indicator the project is downloading is a bouncing icon in the task bar. Since this is often a sign that a program has entered an error state, it's easy for a user to mess up the installation by quitting out of the program while it's downloading. The restore command helps with this, but it would still be nice to have some form of GUI element to show that the program is downloading.