Looking for React project ideas for my portfolio

Hi everyone! I'm a rails developer with 6+ years of experience and I'm currently learning React. I've enrolled last month in the React Nanodegree (Udacity). It teaches React, Redux and React Native. It's going pretty well, I'm finally understanding how redux works! Once I finish the program I also want to create something of value to practice my new skills and have more projects in my portfolio/github profile. Can you please suggest any project idea ? Is there any website where I can search open source projects for charities/NGOS by stack ? That would be amazing