Hexaflexagons is a free iPhone app developed by VUXO I CORP. It falls under the category of Education & Reference. This app is designed to help users create and design their own hexaflexagons, which are paper puzzles with hidden sides.

Hexaflexagons are a unique type of puzzle that have a front side, a back side, and hidden sides that can be discovered through folding. It's a fun and interactive way to challenge your friends and see if they can find the hidden sides.

The app allows you to customize your own hexaflexagon or choose from a variety of pre-designed templates. It's perfect for sending secret messages, creating personalized photo gifts, or making unique birthday cards.

Please note that while the app is free to download and use, there is a limited trial period. After the trial, users will need to upgrade to the unlimited version for $3.99 in order to access additional designs that can be printed and folded at home.