Originally Posted by Xyro
(I'm not a developer or anything, so forgive me if I'm oversimplifying things but...)
Surely it's just the fact it's being installed via the market app that makes it special?
I tried installing an .apk via the market, saving it elsewhere, uninstalling from the market and then installing it manually. The .apk was rejected as being a non-market app, so that tells me there's nothing unique about the apk; the fact that it's being installed via the market is what's important.
I have tried to install an market app which was moved to my sd card by using the app FileManager and because the option Unknown sources
from Settings-> Applications was unchecked then I wasn't able to install it, if the option is checked then i was able to install the app. That means that there is a link between the app and Google market but how it looks and works that's the question ? Also this option is not on AT&T devices so the main thing is in that link, or something which allow installation to go trough ...