Fixes for Lifeproof Fré Case
The Zagg glare and smudge resistant shield DOES eliminate the newton rings (rainbow effect). Also helps with the glare if you are by the pool, which considering you have a waterproof case, you just might be by the pool. Wild guess. Although Lifeproof says not to use it, the Zagg has no negative effect on the case or the sensitivity of your touchscreen. Works like charm. Just to be clear, you install the Zagg on the phone, not the case. For some reason I feel like I need to point that out.
The next topic is the buzzing in the ear while you are talking to someone. I recently posted to cover the mic on the back (mic used for noise cancelation) with scotch tape. This does eliminate the buzzing, however the same mic is used for recording video (unless you are using the front camera, i.e. FaceTime) as well as the mic that is used for speakerphone. Covering the mic with tape will keep you from using those features.
I recently tried turning off the noise canceling from the iPhone setting. What I was able to discover is something called "hearing aid mode".
Go to Settings> General> Accessibility> Hearing Aids> then turn the hearing aid mode ON.
So far so good on the buzzing.....while allowing me to still talk on speakerphone and record sound with video. Keep in mind that those sound qualities are limited already because of the case. If you record lots of sound, say like a reporter doing an interview, you can probably buy a external mic that plugs in like headphones. Just another thought.
Good luck with your LP cases. I know that they aren't perfect, but if you find that using these techniques gets you past the case's flaws, then just maybe we are finally getting somewhere.
My next challenge is to find a way to keep the screen cover from bowing (or bubbling) up. This happened before the Zagg was added, so I know it's not causing the effect. It seems that over time I start to get a bubble right over the home button. My guess is because this part of the screen is used the most, unlocking the phone and whatnot.