Simplify moves all of Gmail’s sidebar icons to discrete drop-down and pull-up menus. It relocates the search feature to a less prominent location and moves core functions, like delete, to the top bar. It also eliminates color-coded labels, and places the create new mail button in the bottom right corner, where the new mail window opens.

It’s all about improving Gmail’s user interface, which Leggett has been trying to do for more than a decade. As Fast Company reports, after leaving Gmail, Leggett co-founded Inbox, and later, while working on products like Messenger for Facebook, he continued to think about Gmail. He developed extensions to redesign other sites, and when Google killed Inbox, he decided to share Simplify.

The extension has reportedly been downloaded more than 15,000 times, with about 500 new installs per day. It doesn’t deliver ads or collect analytics, and Legget has shared the code on Github. He’s had an offer to sell, but says he’ll keep Simplify free — though he hasn’t ruled out creating a separate paid service.

Image: jdayellow @ Reddit

The notification includes a link to open the Gmail app as an attempt to ensure that current users continue to use Google products. Gmail for mobile already has some of Inbox’s most useful features, such as Smart Reply, Smart Compose and Follow-ups — it also recently went through an all-white redesign that made it look and feel more like Inbox. Unfortunately, fans will have to give up Inbox’s bundling and other features that have yet to make their way to Gmail until Google decides to bring them over.