I just released my first Android Application through the market. I'm currently working on some new features for the next release and would like to install this "dev build" on my phone, without uninstalling the "production" version (among other things, this will stop future updates from the Market).
I'm especially interested in this because I'd like to give the APK to friends / "beta-testers" to try, but I don't want them to uninstall the released application first.
Is there anyway to have on one device two applications: "App (via market)" and "App (DEV)"
Would this involve using a different signing key or modifying the manifest in someway?
You can simply rename the package, so both apps are installed.
You need to change the package name in the manifest as well as in the source folder. Use Eclipse's refactoring for it and it will be done in a minute.
They don't need to be signed with the same key.