Have you ever dined at a restaurant and felt frustrated because of the waiting or figuring out how to split the bill? To address this problem, we created a Slice, a mobile app that improves the billing process by eliminating waiter interaction and allowing users to split bills easily.

My Role

Interviews, survey, low-fi & hi-fi prototyping, logo design


Research, interviews, survey, competitive analysis, ideation, sketching, prototyping, testing, and evaluation


Sketch, Origami, Principle

Design Question

How might we improve dining experiences at sit-down restaurants?

User Journey of a Diner

We created a user journey of a diner to help us visualize the areas we needed to target for our research. Potential sources of frustration are highlighted in orange.


Research Findings

We conducted 5 semi-structured interviews with diners and waiters combined and created a survey that got about 30 respondents. We aimed to understand the dining experience starting from your first interaction to paying your bill.


What interactions do people prefer not to have a waiter for?


Our Solution

Based on our findings, people desire a customized service with human interaction in regards to food, but not when it comes to payment. Therefore, we need to give users control over the billing process by accessing the POS system that waiters already use. Today 81% of restaurants use a POS system and are advanced enough to integrate with other software.

Competitive Analysis

To understand how billing is currently being addressed, we looked at our direct and indirect competitors. None of them address the entire billing process or allow diners to pay to the restaurant.


2x2 Matrix

An ideal comprehensive solution can automatically access the billing data and make payments. We used a 2x2 matrix to map out how current solutions addressed both. Since none of these solutions successfully offer both, we knew that Slice could offer unique value on the market.


Paper Prototyping

Using paper prototypes, we conducted guerrilla testing and iterated on our design for the high fidelity prototype. Our participants gave us great feedback related to system visibility, recognition, and user efficiency.


What does Slice do?


Jane is grabbing lunch at Little Thai with her best friends. She logs in to Slice and shares her ID number with the waittress so she can connect to Little Thai.

The waittress inputs her ID into the POS system and takes their order.

When they are done eating, Jane opens Slice and adds her group, Best Friends, to the Little Thai bill so they can also pay directly to the restaurant.

Jane's friend Ian gets a notification and sees that Jane added her to the Little Thai bill. He accepts and views the bill.

Jane selects pay by item. Jane and her two friends each select the Thai noodle because they shared it. She sees the price divide into 3. She also selects two orders of the Mixed Vegetables and a Crab Delight. She views her individual total, selects her tip amount, and pays.

After everyone pays their portion, the app notifies each diner that an item was unclaimed. Ian realizes that he forgot to select the Grilled Salmon, so he selects it and pays for the item before Jane's card gets charged.

some challenges with pay by item

As we created our hi-fi prototype, we encountered some challenges with the pay by item and error prevention scenarios.

Portion Splitting Version 1

Originally, we used a drop down menu to indicate duplicate orders of the same item. Diners select the quantity they want to pay for. However, this does not allow diners to split one order of the duplicate items.

Portion Splitting Version 2

We came up with another drop down menu that allows diners to select the duplicate items individually. Diners that want to split a Mixed Vegetable just tap the same one their friends tapped. Howeover, when we tested this version users found it unintuitive compared to version 1.

New Portion Splitting

We went back to version 1 and added an option button so that users that want to pay a different quantity can enter the exact share or dollar amount.

Some Assumptions We Made

We assumed our users are going through the billing process at the same time, and will be able to easily communicate with each other what items they are splitting to pay the right amount.

What I learned

People care about money but also want to be socially conscious and will not discuss money until the bill arrives. We made sure our solution allows diners to focus on eating and socializing so they don't need to open the app until they want to pay.

Further Development

The split by item scenario could get complicated because of all the splitting possibilities, so it needs more usability testing to be successful. We also have not tested our solution with a group of users that are splitting the same bill. I am sure there are still cases we have not anticipated.