Standard calculator interfaces are too boring and retro. Instead, why not opt for extremely retro — and sync it to your brand new iPhone?
The iPhone Abacus app was created by a Japanese developer, and simulates use of the ancient calculating system that originated in China. Simply move the “beads” on the abacus depicted on your iPhone screen, and math is made easy!
The iPhone Abacus can be downloaded into your phone — and it should be noted that this is not an official Apple app.