You can build many useful web apps with just a few files. You can also extend this simple notes app to add more functionality ...

You've probably used the original Windows Sticky Notes app. It first appeared in Windows XP Tablet Edition in 2002, and it's become the go-to place to jot down notes, ideas, and so on.

Just like any chat app, you can start typing and hit “send” to write a note or a thought. There is a handy checkmark sign above the textbox, so you can easily create a checklist or a to-do list.

Napkin is available on the App Store with a fee of $6 per month or $50 per year. You can also get a seven-day trial to test out the app. The company says that the app doesn’t want to disrupt ...