Sorry, I should clarify. I am looking for an app that flashes the camera flash for incoming calls. This was built in on my Samsung Note 4 (an option under accessibility settings). Before the Note 4, I had used a third party app on Motorola android phones. None of the apps that I have tried will get the flash to light up on the 6p.
I was able to get the lightflow app to flash the camera LED, however the app either has "no control" or "control when screen is off" options for the camera flash LED. Since the screen is on with incoming calls, the flash won't blink until you silence the phone and the screen turns off, thus it really isn't useful for getting your attention.
The app suggested by renegad3 was exactly what I was looking for, thanks! This app has the ability to change the "module driver" as the default standard setting didn't work, but switching to an alternative works.