OneNote, EverNote, Google Keep, and many others – Which of the many note apps you like depends on your preferences for interface. The major ones have many of the same features. Google Keep is noteable in that it is totally free and in the Google ecosystem, which provides 15G for free. Common features in note apps are grouping folders, color coding, reminders, importing media, and connection to calendars.
Zotero is a citation management system. It keeps your full-text connected to the citation, so you can find it easily. Notes are also grouped with the citation. You can assign tags and search by tags. You can leave yourself notes, such as “Need to ILL,” then search on that note. You can leave notes in folders to remind yourself where to pick up on the work tomorrow. Finally, you can read and mark up PDF files.
Save your favorite articles or books and organize them using multiple labels.
To organize your life, noting everything from class time, work schedule, and study time allows you to plan for fun time. Or you can try something like Timetable, myHomework, or Studious which are geared for students. Or you can try AppDetox, SelfControl, or StayFocused to turn off apps during your study time.