I recently created a web part for SharePoint Online that retrieves the current user's Office 365 Groups and generates a list with thumbnails and links to that group's SharePoint page.
I have submitted this web part to the SharePoint repo on GitHub and it was accepted! Feel free to check it out: React-My-Groups
Update: I participated in a community demo on 11/21/19. You can find the video at the link below, in the video you will find the latest updates for SPFX and two other awesome web parts that were demoed.
I will be posting a series on the development of this web part so stay tuned! This series is almost ready and will be posted soon!