I've started writing flash fiction. Or microfiction, you might hear it called. Very, very short stories. The first one I've written was 112 words.
Incidentally, I've finally started using the Instagram account I've had for months. I've never been one for posting selfies, and I don't have anything interesting to take pictures of. So I've decided to write very short stories, put them in a square with a nice background, and post them to Instagram.
Just like books are divided into length based categories (novellas, novels, epics), so too is flash fiction. The term "flash fiction" itself is used for stories 1,000 words long. "Sudden fiction" is 750 words, "microfiction" is 100, and a "minisaga" is 50. A lot of them show up in literary contests where the goal is to have exactly that number of words.
I'm not so particular, so I'm using "flash fiction" in the general sense. I'm not so much constraining myself by word count, but by overall size.