Intentional Camera Movement (ICM) is an abstract style of photography where the camera is deliberately moved during a long exposure. It produces an artistic effect that's a bit like Impressionist paintings. I've tried it a few times with my DSLR, with mixed results. Recently I found out you can get a 'slow shutter' app for smartphones that allows a long exposure and so enables the possibility of ICM. I enjoy playing with my iPhone and found it relatively easy to produce pleasing (to me anyway) images using the technique. Autumn is a good season for it as there is a lot of natural colour around.
ICM is quite addictive at first. I think I'd soon get bored with it if this was all I did but like most 'techniques' it is fun to experiment and learn. Some photographers have made it their signature style and produce images with a lot of 'wow' factor.