Think of something you’ve been studying lately and have to memorize—maybe the periodic table or a sequential list of steps. Find a way to condense it, so the material is the size of your phone screen—then make it your background. (Alternatively, make it the screensaver and background on your computer.)
Every time you check the time, glance at your phone, or get a notification, you’ll see the material. Take a few seconds to read it over. Now, it’s ever-present. Any time you want to review or quiz yourself, just tap your phone, so it lights up. You won’t have to dig through screenshots or notes to find what you need.
This also works for instructions, say, for an essay. Instead of continually opening up the instructions page, just keep it handy as the first thing you see on your phone, so you can check your work and progress as you go.
It is often possible, too, to have screen backgrounds that change. But it is a great way to just have something subtly reinforced for learning throughout the day. Even in your downtime, though, you can be subconsciously absorbing your materials.
See How Your Phone's Background Can Help You Study
This simple trick combines active learning and passive learning.