This is the Classic Sticky Notes app Microsoft omitted in the Windows 10 Anniversary Update.
More about Classic Sticky Notes
With Windows 10 Anniversary Update, Microsoft discontinued the classic Desktop app "Sticky Notes". Now, its place is taken by a new app with the same name. The new Sticky Notes app is a Universal (UWP) app, which comes with different features but as is Microsoft's way of doing things, it doesn't include all the features of the classic app. For example, the new app lets you create Cortana reminders from your notes. You can type a phone number and have it recognize it, and recognize URLs too which you can open in Edge. You can create check lists and use it with Windows Ink. Starting in version 3.0, the modern Sticky Notes app includes a dark theme, the ability to sync notes between your devices, and tons of other new features. Learn more.
You may also be interested in...
What is Simple Sticky Notes? It's a simple, easy-to-use, absolutely free, fast and efficient note taking software.
Evernote is a free note-taking application for Windows, Mac, Android, iOS, WP, and BB with cross platform support.
hrow away the traditional paper sticky notes and start using the powerful and unqiue Efficient Sticky Notes.