I installedQR Code Generator form the test marketplace. When I clicked on the icon on my home screen there was a noticeable delay in launching the app (on first run). I assume the delay is due to the need to download and cache the resources. To be consistent with the Android platform, it seems to me that the app should be downloaded and cached when it is installed in order to allow it to start faster.

After trying River Raider, an alternate suggestion is to at least show some sort of loading screen while the app is being cached.

Duping on the startup perf bug tracking the work for this.