Here is an app I found looking for something else. It appears the app was launched in June of this year.

According to the description of the app:

20Stamps is a new app that lets you personalize your letters with customized stamps. The app lets you add your own photos to stamps, which you can then order on a 20 stamp sheet.

The stamps are officially licensed by the USPS to be valid anywhere in the U.S. at the going rate of $0.49. You can add pictures of friends, family, pets, vacation spots, or even images depicting what’s in the letter. The app includes over 30 pre-built designs for varying special occasions to offer more choices. You can apply filters to any photos that you add, and also pick the orientation.

There are ten different postage rates to choose from, but for a base line, a sheet of 20 $0.49 stamps costs $20.55, showing each stamp costs double to customize over buying standard stamps. It also costs $3 for standard shipping, but the app includes 15% off coupons just by sharing through social media.

The app requires iOS 7.0 or later. It’s compatible with iPhone, iPad, and iPod touch and optimized for iPhone 5. The app can be downloaded for free from the iTunes store.

note: This is not an advertisement