I started putting in what I call my "dev gui" for the build just to make sure everything is working. I recently had a problem where everything worked in the editor, but there were problems with the build, so I stuck in a bunch of Debug.Log for while I was running in the editor, and I also had it write it to a gui in world space but outside of camera view, then I just did a keypress listener to move that gui in and out of the camera view. I found the problem lickety split. So now I use it all the time. It's not the ideal solution, but it less time consuming than digging thru the app data to find the problem