Google Keep on my phone and in my browser to organize my thoughts with color coded notes. I've used Keep for that purpose off and on for the last six months. The knock against Keep has been that while color coding helps organize notes it would be better if you could label your notes too. The latest update to Keep will let you do just that (the update is on the web version now, the Android version is coming soon).
I also use Keep to set reminders on my phone. The update for the Android version Keep will allow me to set recurring reminders for tasks and events.
Applications for Education
Setting recurring reminders on Keep could be a good way to help students get in the habit of reading or studying at a consistent time during the week. Using labels and color coded notes in Keep could be a nice way for students to construct an outline for a research paper or presentation.
H/T to Lifehacker for the updates.