For the Olin course, Human Factors Interface Design (HFID), I worked on a team of 4 students to develop an iPhone interface for parties who wish to split bills at restaurants.  The project took the team from broad user studies concept generation, to both low and high fidelity prototypes of the interface of our system.  Throughout the process we used tools and techniques including paper prototyping, cognitive walkthroughs, and hueristic evaluations.


Payr is an iPhone app which allows restaurant goers to quickly and easily split bills among friends at a restaurant. When we analyzed the needs of restaurant goers, we realized that there was a strong social aspect to paying for bills at restaurants.  Some individuals would always put in extra to make up for others, while others were determined to pay their share and not a penny more.  But universally, people wanted to pay their fair share and most importantly, did not want to look cheap.  Users did not want a tool that would tell them they needed to pay $17.29, because this made them feel cheap.  Based on this personal (but social) nature of paying for meals, we developed Payr.

While there are many tools which keep track of debts among groups of friends, in our observations and interviews, we identified that there was an opportunity that focused on the bill paying experience.  Because of this, Payr is designed to do one thing- split bills at restaurant.  The simplicity of the interface and the ability to lose precision makes it quick to use, and removes many of the social stigmas around someone taking a calculator out to calculate how much people owe.

The main interface for Payr is built around dragging food items to people and is designed to encourage conversations of “Who had the ___?”  This basic interaction with a few sliders to add in tip and a “Round” feature which provides patrons with “nice values” calculated to the quarter or dollar.  At its core, we looked to make Payr as simple as possible.  We don’t allow each patron to pay a different amount for the tip because it adds unnecessary complexity.

More information about Payr and a high fidelity mockup are available here.