I had a specific need. I needed a bomb sight correction calculator.
When I have some spare time, I fly the IL-2 Sturmovik, which is a wonderful, action-packed WW2 air combat simulator. On servers there may be up to 50 pilots in the air, flying a wide array of aircraft, and serving a number of roles. Some are fighter pilots, some fly ground attack planes, and some, like myself, fly bombers. My favorites are the Japanese Mitsubishi G4M Betty and the German Ju 88 and Heinkel 111.
The game is so well made that it even includes a bomb sight for accurate bombing. This device relies on the altitude and airspeed to decide when is the perfect time to release the bombs. It takes quite a lot of practice to master the device, but when you know what you are doing, you can plant a bomb in the target with relative ease and precision.