Can I use the standard European two prong plug adapter in Germany, Austria, and Switzerland? I have read that Switzerland might use a different type.
My wife and I stayed in a Swiss Airbnb in June, where the standard European two prong plug adapter did not fit the sockets. We needed a "flattened hexagon" like one on the left of the image in the link. There are also adapters-for-adapters that plug into Swiss sockets and allow you to use the standard European ones. These are supposedly for sale at airports, though we were blissfully unaware and just lucked out that the Airbnb place had adapters in place.
Switzerland uses a "J" type adapter. Germany & Austria use the "E/F" type adapter. You can check on Amazon for photos of the difference.
I would recommend picking up two of each - sometimes they come in a 3-pack anyways. So, you can plug in your phone, camera, etc. each night.
Last time I was in Switzerland couple years ago, I used the exact same plug adapter that I used in Germany and the rest of Europe (excluding Great Britain). It was the $1 one sold by RS and it worked without any issues at all.
Ditto what Mark said. No problems at all.