As others have said, microwave ovens create standing waves with regions of higher power (hot spots), which unevenly heat food. If you want to see this for yourself, Scientific American has a kids project for measuring the hot spots in a microwave using chocolate or marshmallows. There’s also a bunch of videos on YouTube of people essentially doing this same project.
lol I just checked and I had 26 pending app updates. Every one of them had about the same level of detail.
The only exceptions were the Wikipedia app and Voyager, both of which listed some new features.