Need a simple way to keep track of thoughts, tasks, and lists? (Who doesn't?) Google's Keep app gives you a dead-simple interface for recording, managing, and sharing all the little things in your life.
Keep allows you to jot down notes or leave yourself memos via voice and have them transcribed automatically into text. You can snap photos to include with notes, too, and even search later to find any text visible in those images.
Keep has a bunch of other useful bells and whistles, including a checklist function, the ability to tag and color-code items (then sort by those variables for easy access), and the ability to set location-based reminders for specific notes or lists. The app also makes it possible to share notes or lists, then collaborate on them with others in real time.
Perhaps most important, Keep works on any platform -- and everything you do is always synced across all of your devices.