Need advice how to get good ideas about side projects

I am really inspired by lot of things going on about side projects to enhance the skills. I really want to do some side project and open source it. I have tried many times and I am successful with one of my project. https://github.com/codestergit/SweetAlert-iOS But I want to start a new project but do not know where to start and what to build which actually worth my time. Need advice how you start with your side projects and how do you find the ideas to do new things. I really appreciate if some one help me or give some advice.