StepStack is an iPhone app developed by StepStack Ltd. It falls under the Lifestyle category with a focus on Health & Fitness. The app is free to use and offers a unique way to stay active while supporting great charities.

With StepStack, users can set personal targets, track their progress, and share their achievements with others. The app rewards users for their extra steps by converting them into StepStack coins. These coins can be used in the app's marketplace to access special deals from commercial partners, or in the auction room to bid for exclusive products from partners.

One standout feature of StepStack is its charitable aspect. Users can choose to donate their StepStack coins to one of the app's charitable partners, and StepStack will match these donations with cash. This allows users to make a positive impact while staying active.