I found the following inserted into Info.plist in the weather.app and had to remove it to get the app to exist again on the springboard.
[key]SBAppTags[/key]
[array]
[string]hidden[/string]
[/array]
(I changed angle brackets to square brackets in the code so it would show up properly)
I think the culprit is probably the latest Evasi0n update.
Yes, I have an iPad, yes I ported the app over by hand from my other iOS device, yes, Evasi0n should leave it alone. Why does it hide the app?