Coffee'd makes use of a React-Redux frontend, React-Materialize for styling and a Rails API backend to remind users to make plans with their friends based on when they've last seen each other. This was inspired by a common problem that a lot of people face -- it's hard to remember when you last hung out with one of your friends! (It's also hard to decide on a place to go to.)
Coffee'd seeks to solve both of these problems by gathering this information in one spot, so you don't need to cross-reference your calendar only to realize that you agreed to hang out with Larry at the same time you promised Sally you'd bingewatch TV with her.