This is overkill, but you could print the paper ones out at home, and try to use the electronic ones. If the electronic ones don't work, then you have the paper ones as backup.
One suggestion... make sure you know how to call up the boarding pass. When I used the Delta App last year, I kept clicking on the wrong place to call up the BP. It took me a couple minutes (TSA wasn't familiar enough with it to help) to figure it out. No, there was no one behind me at security.