A free app for Android, by QR Scanner QR Code Generator Radio Notes.

If you’re looking for a simple and convenient way to make a note or two, then this is the best app for you. It’s a simple and intuitive way to make notes without having to do any extra work. You can easily make a list of things you need to remember, write down an idea for a book you’re reading, or even draw a picture to help you remember what you wrote down.

You may choose a theme for your notes so that you can easily categorize them. With this application, you can now write some notes and lock it to make it secure.