Role: UI designer and UX researcher

Project Duration: September 2021 - December 2021

Cart-In is a mobile application that provides payment incentives for customers to return their carts back to the cart trolleys. The incentives are received after scanning or inputting their cart’s QR codes upon return. The goal of this application is to limit the disorganization of loose carts, which in turn promotes better business practices and appearances.

This application was ideated, designed, and composed by me in my last year of attending California State University, East Bay. This was my second project created alongside my senior capstone project, YipYap. Unlike YipYap however, the idea for Cart-In was assembled through my own brainstorming. While there are similar applications that provide payment incentives for doing specific tasks, this application that I created is the first in the market (assuming this becomes a live application). I chose to create Cart-In as a way to challenge myself to compose an application that has little to no direct competitors. My branding is based on modern design practices and colorways, and the navigation of my application is based loosely on indirect competitive audits.

Problem Statement

Problem Statement

Problem Statement

Some grocery store customers in the United States have an issue with returning their shopping carts to their designated areas after unloading their items into their vehicles. One of the many solutions was to create a mobile application that will provide payment incentives to return a cart as a way of decreasing this issue.

Target Audience

Target Audience

Target Audience

Grocery store and supermarket customers account for the largest sample of persons going into retail areas with parking lots, but they also make up the largest percentage of those who tend to not return their carts at the end of their shopping trip. Based on my research, people who shop alone or individually have a higher chance of not returning a cart since they feel that they face zero to no consequence from their surroundings. Smaller groups and families with older and younger children, however, follow second to this statistic but are less likely since there are more people around them.

Although this application aims to provide a solution to a large shopping issue, adults are the likely age group to utilize this application. I gathered my research using both a small group behavioral interview as well as a larger quantitative interview given through an online survey. I sampled a total of 83 participants, the majority of which were men between the ages of 25 to 40 years. Women and those who identified as neither gender made up the remaining percentage, and these groups were composed of individuals ranging from 21 to 38 years of age. Everyone who participated grew up on the West Coast and attended some form of a college education.

Competitive Audits

I looked into three other applications that utilized payout options for when users logged specific tasks into their apps. Sweatcoin and Ibotta reward users with store credits and cashback, whereas CoinOut offers cashback when scanning a store receipt. Cart-In aims to employ all these features with every cart returned, with the added component of a physical payout exchange for those without access to the application.


> What drives a person to physically want to return a shopping cart after its use?

> Why do some individuals choose to leave their carts unattended and loose instead?

> What difficulties do people run into when confronted with an unattended cart, and do they then choose to return the carts on their own accord?


> How often do you go to the supermarket and see unattended and loose shopping carts?

> Do you currently have any side habits and services that add to your existing and routine income?

> Do you currently possess any mobile applications that pay the users for performing certain services? If so, please describe any of the options that you own.

> What is the minimum amount of payment you would accept to perform a small task, one such as returning a shopping cart back it its designated area? Do you think someone needs to be paid to return these carts?

> How often do you go grocery shopping? Are you usually going by yourself or with a group?

> What do you consider the drawbacks to downloading these apps? And, are you more inclined to possess an application that pays you back in digital cash or through discount and referral codes?

> Do you trust applications that offer to pay you for doing things? Why might you not trust these applications?

> Are you more inclined to trust a payment application that uses a third-party transfer or is it preferable to have it accessible to your direct line of credit?


1. Returning a shopping cart is more than just a physical action. It plays into an individual’s moral character in helping others and themselves.

2. Incentives are the largest phycological motivator.

3. There are many reasons why someone might not want to return their carts, and some of those reasons have to do with safety and capability.

Persona(s) & User Journey Mapping


Jane goes to the grocery store as part of her weekly routine and after unloading the items into her vehicle, she returns the shopping cart back to its station, takes a photo of the QR code of her cart and returns to car where she will open the application to complete her final transaction.


Johnny is making his daily deliveries and chooses to go to the local supermarket for his lunch. On his way back to his vehicle, he returns the shopping cart that someone had left nearby his parking space, takes a photograph of the cart’s QR code, and finally returns to his vehicle for his transaction.

Defining the Design

The MosCow Method


Design & Testing

Low-Fidelity Wireframing


I showcased the personas and initial prototyping to three other students. They collectively agreed that the home screen should contain other options in the middle of the screen as opposed to having just one button. Additionally, they were concerned too about the layout of the home screen, as it resembles more like a desktop application rather than a mobile application.

Mid-Fidelity Wireframing

Happy Path

I was able to present the next stages of the wireframing stage to the same three individuals from the initial iteration. With a more detailed look into the functionalities of the working application, the feedback had been more positive in regard to the updated features and user actions. They agreed that the added side and/or hamburger menu was ideal for switching between the pages and that the sizing of the buttons and text was easy to read.

Navigating through each page seemed simple enough given the hierarchy of images to buttons. Taking note of their feedback will help me in designing the last stages of the wireframes.

Final Design Screens

Error Case

With the colorized and updated version, the final feedback I have gotten was positive in regard to the additional features. Users were satisfied with the login, terms, conditions, and password features provided before entering the home screen. The navigation bar on the bottom of most pages is consistent and easy to use.

Edge Case

Many of the issues that can erupt are logistical cases that can occur outside of the scope of this project. One of the major issues is limiting how many carts can be pushed inside the cart trolleys at a time before the system fails to read it as a cart that has been returned. Another case is determining whether a cart that has been taken out and inserted again immediately afterward would be considered a viable transaction.



My recorded interviews were not specific to my target audiences. I was limited to the small number of users in my college class, and since many of them were young adults the design perspectives were likely skewed by their similar interests.

Going Forward

I will definitely prioritize other online sources for future projects involving research and interview. In regard to presenting the finalized research, I will also refer to other product design references in ensuring that my application is concise yet displays enough information for the audience to understand the process.