I did some more digging into Google Analytics, and found that the crash in Auto Respond was occurring on tablets. All 3 crashes were on a tablet device.
With that said, I'm not sure why anyone would even be using Auto Respond on a tablet so I was a bit confused. Plus, just for kicks, I ran it on my Nexus 10 with no issues, which confused me further.
I was, however, able to recreate the issue on a 7-inch tablet in an emulator. The issue is that a 7-inch tablet failed my check to see if the device is a tablet, and it loads a layout over top of the existing layout - which causes a crash on a tablet settings screen layout, which is why I have that check in the first place.
The good news is, since I used the same code in my Tic Tac Toe game, this avoids an issue if THAT is used on a 7-inch tablet (which is something that is very plausible)
So all 3 apps have been updated (Auto Respond - free and pro, and Tic Tac Toe) to a version free of crashes, and a few minor other updates in each.
These changes have just been pushed to the Play Store, and should be live in a couple hours.