Add a feature to “ULABOX” App

UX/UI Design Case Study

Guille Darriba
6 min readDec 9, 2020

TL; DR (too long; didn’t read)

We designed a new feature for the existing app “Ulabox”. This application is an online store for market products, whose scope is Barcelona capital and it has the value proposition of working with numerous local markets (including its own) and delivering the order in less than two hours. The new feature that we will study consists of “being able to make purchases as a couple, where each member can add products to the same shopping cart”.

“Being able to do the shopping online with my partner without having to break my head guessing which is the model of pads or razor blade that she/he likes the most? Count on me!”


Brief: Adding a feature extra the app to Ulabox; being able to make the purchase together with another person or with several people and that everyone can add products.

Product: App.

Project time: 5 days.

Applied methodology: Design Thinking.

Tools used: Research, Interviews, Surveys, User Persona and Scenarios, Use Cases, Crazy Eight, Wireframing, Task Analysis.

Team: Solo.


After conducting research on Ulabox and its context, the primitive results were as follows:

· Product: Ulabox is an online market product sales app/website, with delivery in the same day, and products from its own warehouse and from various local markets in Barcelona. The current delivery area is just Barcelona capital.

· User: The most common user profile at Ulabox is a 25–34 year old urbanite person with little free time to go to the market, although there are many profiles among its more than 350,000 users.

· Direct competition: Lola Market, Deliberry

· Benchmarking: Amazon Prime Now

Data obtained from here (spanish pdf).

To start researching the project, we needed to answer what would be the research hypothesis;

“How do young urbanites between 25 and 34 years old with just little free time to go to the market organize their market purchases together?”

By answering this question we will obtain important information to tackle the problem.

Barcelona local market.

To do this, we did surveys and interviews as methods of empathizing.

Of 74 people surveyed, the most significant quantitative results were the following:

· 77% share their market purchase with someone close to them

· 80% go to the market together when they can

· of which 83% go through the market together selecting the products

· 70% have a common payment method

No, shopping with your partner is not this happy.

The most powerful insights obtained from the interviews with 6 people were:

·“Many times, I get stressed due to lack of free time in common with my partner and not being able to carry out daily activities together such as shopping”

“If I go, it only generates frustration for me to return with some less product that my partner needed”

“I would not use a joint purchase app for barbecues or occasional parties; I would only use it when doing the usual shopping with my partner. “

“To pay for the purchase, we always use the credit card we have in common”

What a healthy face, ugh?

With these results, we elaborate the User Persona and its possible Scenarios.

Carmen Alfaro is 32 years old and considers herself an urban woman. She comes from Seville but has lived and worked in Barcelona for six years. She works in human resources in the IT sector and is up-to-date in new technologies.

She has a partner and they share a flat and expenses.

She likes to buy fresh product from the market but cannot do so regularly because she is too busy, like her partner, and because of the long distance to the local market.

How can we help Carmen Alfaro?

Possible Scenarios or contexts that we studied were as follows:

· In the market, she physically buys product from there.

· From the office, in a hiatus from her work, Carmen uses her phone to buy market products online while her partner is elsewhere.

· From home, sitting comfortably on the sofa, she uses her laptop to buy groceries online and her partner is using the phone next to her.

Research Question

What can I do to make the Barcelona urbanites aged 25 to 34 years with little free time do not feel stressed when trying to buy market product together with their partner in a telematic and quickly way?


For the Ideation phase we use the Use Cases method. We proposed the following objectives of each Use Case. We transformed the first one into Lo-Fi wireframes:

· The user wants to make an online purchase together with his/her partner.

· The user wants to temporarily change partner in the app.

· The user wants to modify his joint purchase already confirmed.

Once you devised the happy path and also studied their alternative paths, we started to sketch wireframes to test them with users and know their point of view.


To design the initial LoFi prototype, we used the Crazy Eight method. As a result of ideation, we implemented a new button called “Duo Shopping” that activated a small modal where you could set up this new feature.

The modal window included the activation and deactivation) of the feature, and the configuration of the link with the account of the user’s partner. The system consisted of two users with the app of Ulabox and Duo Shopping linked (via emails) and activated could add items to the same shopping cart. All this history began to see the light!

We transformed this idea in various LoFi wireframes.

Some of the Crazy Eight results.

Once we finished the wireframes, we tested them with five users. We obtained the following results:

· The name “Duo Shopping” convinces and is liked. Users understood well the copy.

· Change the icon used to add Duo partner (it was a pencil and it was changed to a plus sign “+”).

· Change the order in which the options appeared; first to enable the Duo Purchase to be activated and second to add or modify the Duo partner.

· Implement a new option that consisted of the automatic deactivation of the Duo Purchase after completing each purchase, so as not to make joint purchases in an equivocal way.

· Add another button to access the Duo Purchase modal from the shopping cart window.

LoFi wireframes and flows.


Once we finished testing and having obtained these conclusions, we designed in HiFi the final model of the feature, respecting of course the graphic style of the app. In a very few taps the option was fully configured.

Final HiFi wireframes.


For the near future, the next steps or ideas to test and study are:

· Make the onboarding of the new feature, in order to explain its use to new users.

· Also add access to the modal Duo Shopping from the page of the shopping cart (yet to make, despite having obtained results in tests with users).

· Extend the shared purchase to more than two users.


From all this Project, the most important thing we have learned was:

· To differentiate target users of the investigation process from target users of the use of the app, that means, to carry out the market purchase investigation regardless of whether the users questioned use the Ulabox app or not.

· To limit the features to the type of population that they are going to use; in this specific case, couples. At first, trying to make a joint purchase with an infinite number of people was a waste of time and an a unnecessary complication of the project.

Thanks for reading! ⚡



Guille Darriba

📱UX/UI Designer ⚡USER-CENTERED digital content creator with an extensive background in Graphic Design and Drafter CAD Design. 📧