The splash screen freezes on the device if:
1) a third-party module (e.g. tested with https://github.com/appcelerator/titanium_modules/tree/master/flurry and also custom module with no real content) is included in the tiapp.xml file AND
2) the device is connected to a WiFi which cannot access the internet
On the simulator, everything works fine. I have no idea why this is happening, but I tried to clean the build several times and have even created a new plain project tracking down the issue to these 2 points.