90 Days is a simple, flexible tool for note taking. Pick some part of your life or habit that you want to change and pay attention to it for 90 days. It could be getting back to the gym, eating better, quitting smoking, or anything. Jot down a reminder, give yourself an attaboy/attagirl, keep a journal, etc.

Pick a start date and go. You can erase a note, erase all your notes at once, or easily delete your whole account. There's no reason not to try it.