Readwise has become essential for me. It's an RSS reader, read later app, and spaced repetition app in one. The idea is that you take in new articles to read, highlight them, and then review the highlights daily via spaced repetition.
It's brought to life for me Richard Feynman's idea that the way to do great work is to keep a dozen questions at the forefront of your mind and wait for inspiration. It's remarkable how often I'll see something in my daily review that helps me reframe my approach to a question.