Case Study — O2 World Chat App

World Chat is an app to make international calls with the best rates possible. It is a service that doesn't need Wi-fi or data to call and it is available to any UK Sim Holder. But there are problems…

Flavio Lamenza
Draft · 5 min read

The Problem

The first time experience is not engaging, leading to 84% of Bounce Rate.

The Challenges

  • To educate a user as to the benefits of the app.
  • To simplify the process of making a 1st time call.
  • To engage users leading to repeat use and reduce bounce rate.

The Solutions

  • To streamline the on-boarding process.
  • To create specific screens addressing the key user's frustrations.
  • To provide an interactive walkthrough for 1st time users.
Interactive walkthrough as part of our solution.

Competitive Analysis

We analysed the major players and their on boarding processes.

On boarding walkthroughs of World Chat competitors

We learned that a memorable on boarding process helped users to feel more comfortable when reading about the benefits of using the app. Also that showing the rates before requesting to sign up encouraged users to sign up with more confidence.

Guerrilla Interviews

Where is the user? As a recap, our app focused on the niche market of making direct calls to landline or mobile of family and friends abroad. And what we did? We went out there! We interviewed and understood 15 expats living in London from the most different backgrounds.

Myself interviewing three Brazilian Uber Eat drivers who called home without scheduling calls.
Raphael interviewing Alberto, a cool Spanish guy looking for a Job in London. (By the way, we met him in a Job Centre)
Nick interviewing two Azerbaijanis students in a Student Hall located in East London.
Adrian interviewing Manuela, a lovely Italian cook in a food market.

Here are some of the quotes from the interviews that we found most relevant:

I never normally schedule calls, I just call whenever.

My Grandad struggles to understand WhatsApp.

Calling cards are just too complicated for me.

I want to know how much it is going to cost me.

Persona and User Journey

With the research information in our hands we were able to build a journey and a persona.

As you can see above, Lena, our Polish persona, arrives in London (where she lives) from a trip to Warsaw (visiting her family). O2 sends her an SMS to advertise the benefits of calling abroad. She downloads the app but finds it too confusing and can't even find the rates to call Poland. She ends up deleting the app.

Stop, Sketch Time!

With the competitive analysis, persona and journey in our research it was time to start sketching and to have crazy (but doable) ideas.

Don't know if there is a UX name for this technique yet…
Yes, we drew giant mobile screens with a table 👌

We also held a Design Studio session with the client, which helped us a lot to generate ideas in such short time frame. Our scenarios were in regards to streamlining the on boarding process.

Sketch ✍ ️+ Low Fidelity + Mid Fidelity + High fidelity Prototypes

We then tested several screens and the whole flow with paper prototypes and the digital prototypes.

We added this interactive screen before the signup process. During the paper and low-fi prototype we tested with a static page showing the benefits of downloading the app, but users didn't pay much attention, they just wanted to know how much it would cost them to call abroad.

In this screen we summarised the requirements of using the app. You can make direct calls to landline or mobile, and to do that you don't need data. We also tested the use of iconography with great results.

In the actual app the user is prompted with the request for his contacts. We tested and realised this was too invasive. We tested with a screen prior to the request giving the reason for doing that. Users told us it made them more comfortable to accept.

The Clickable Prototype

The on boarding process of the app was kept with the same number of steps, but in an order that showed first the benefits of the app and then asked users to sign up. Throughout testing many iterations users understood this was more memorable and more honest approach.

If you have any questions or would like to know more about this process, let me know by sending me an e-mail to