When I have some free time I love to create tools, that help me to solve problems, that I am encountering myself. This page contains references to them.
Easier insert interactive Flow examples in your blog: https://frontendgirl.com/share-flow/.
Chrome extension, with which in any new tab in chrome random word from the Urban dictionary with top explanation will be shown: https://chrome.google.com/webstore/detail/urban-dictionary-random-w/pdbnimldnojnddglfjadfoonnclfjadj. It also gives the possibility to search for the words or idiom definition in the Urban dictionary.
Eslint plugin that contains specific rules for the projects that use React and Flow (eslint-plugin-react-flow): https://github.com/Kiwka/eslint-plugin-react-flow