Our product is designed with safety front of mind. Our rare-earth magnets have a rating of N50, the perfect strength to not interfere with wireless charging and still give a strong, secure hold. You should not be worried as the magnets in the SnapMount 3 will not have any negative or damaging effects on your smartphone. Only industrial strength magnets can damage smartphones.
“there will be no issues at all with the magnets that your phone is likely to come into contact with during everyday use such as those in magnetic cases or cradles or on your purse or handbag”
http://blog.first4magnets.com/will-a-magnet-damage-my-smartphone/