If you use the Samsung Galaxy S-Pen, you might have experienced the problem of losing it, which is a very annoying experience. To prevent this from happening, you need to use the Samsung Galaxy S-Pen Keeper. This is a smart utility for the Galaxy S-Pen that keeps an eye on it and will remind you to attach it if you are moving away without it.

It works as a notification. When you're moving away from your device, you will receive a notification to attach the pen. You can set it to work as a notification from the app itself. It also works as an app, so you can install it on any Android device.