I've been playing with some concepts to improve the way people write on Medium and I came up with a little tweak (using the actual menu that appears when someone selects a word) that could help to non english native speakers (or everyone) to gives some more vocabulary variety on their articles.
I used a fragment of this article (https://medium.com/about/writing-in-medium-df8eac9f4a5e) wrote by Ev Williams.
I must say that i'm not affiliated with Medium and this is just a concept.