A free program for Android, by Litter Penguin.

If you want to take down everything that you have to remember or write down for future reference, Notes – Notepad, Notebook & Checklist is the best choice for you. It is a free and lightweight notepad manager and note-taking app. It can help you to easily write and organize your notes, memos, e-mails, messages, shopping lists, to-do lists, and other lists.

You can quickly remember anything at any time and place. All you need to do is to open the app, write down what you need to remember, and it will be saved for you. If you need to make a list or checklist to help you remember things, you can easily do that with this app. The best thing is that it is completely free, so you don't need to worry about anything.