If you spend a lot of time taking apart APK files, you're probably already intimately acquainted with APK Tool. For the unaware, it's the go-to tool for decompiling, recompiling, and generally tinkering with APK in any way you want. Despite it's incredible functionality, some people still prefer to use a nice simple GUI when performing basic tasks, as opposed to the menu driven interface of APK tool. It's for this very reason that XDA Senior Member elesbb has put together a couple of simple little applications to allow basic APK editing from a GUI.

Both of these programs require Microsoft's .NET Framework 4.5 to be installed. If you don't already have it, links to the installer are provided in the forum threads for each program. Be sure to check out the threads linked above for each tool for more info and download links.