I'd like to share my new app ReNotify (free + ad free)
The idea of ReNotify is to eliminate all the awkward fumbling with your phone when you try to set a reminder on the go. In the time is takes to read this sentence, you can take your phone out of your pocket, open ReNotify, set a reminder, and put it back in your pocket again. It's seriously that fast. Then the next time you turn the screen on, you see the reminder.
It uses Android's built in notifications system which means you can view, dismiss and add more notes from anywhere on your phone, and the reminder icon is visible the instant you turn the screen on.
ReNotify has a clean and simple UI, is free from ads and takes up virtually no memory.
If anybody's interested there's also a paid version with history, editable notifications, and expandable notifications.