We can find out various versatile note apps on App Store. But if you prefer paper notes, the following Binder iPhone 4 case will allow you to attach some notes on your iPhone.
This is an innovative, practical protective case designed for iPhone 4 and iPhone 4S. The iPhone 4S case features hardshell construction in order to protect the iPhone 4 or 4S from bumps and scratches, and as we can see from the images, the iPhone 4 case also features an integrated metal binder on the back, so you can conveniently attach some paper notes on your iPhone as a memo, of course, the binder can also be used as a versatile clip to keep your cash, a smart card securely in place. Apart from that, the custom cutouts allow you access to all the functions and buttons of your iPhone 4.
The Binder iPhone 4 case is available in two types including vertical and horizontal, each one is priced at $25.4 USD. If you’re interested, jump to Strapya World for more details.