Kjosk is an hourly power bank rental based on the principles of the sharing economy. This product solves the problem of the nervous search for sockets and allows you to enjoy your smartphone regardless of the circumstances. Kjosk stations located in different parts of the city (e.g. in shopping malls) are a reliable source of energy and a simple way to be in constant contact with the world.

Kjosk Polska Sp. z o.o.
Czas trwania projektu
from January 2019 to November 2019
Lokalizacja klienta
Wroclaw, Poland
Kjosk Polska Sp. z o.o.
Duration of the project
from January 2019 to November 2019
Client location
Wroclaw, Poland
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The task for me was to develop a concept for the power bank rental service. The contact points of the user with the service are Kjosk stations located in the city, equipped with a touch screen and a payment terminal, and the Android / iOS mobile application. An additional task was to develop a system for employees of the customer service department. The process of registering a new user and renting had to be developed separately for the Kjosk station and the mobile application. The biggest challenge was to ensure maximum availability of the service and to simplify the rental process when the user has an empty smartphone, does not have a Kjosk account (thus no card is attached), and wants to rent a power bank to recharge it. It was also necessary to foresee scenarios in which the user already has a Kjosk account, but has a flat phone or his battery is about to die and he wants to rent a power bank as soon as possible. Also, it was necessary to anticipate the maximum number of possible problems, such as the expiry date of the connected card, payment problems, or damage to the equipment.

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Design process

I focus the entire design process on the user, to understand his conscious and unconscious needs. I try to validate the effects of the design process as often as possible by experimenting on prototypes and frequent testing of hypotheses during conversations with users, so that at every step I can return to the stage of generating ideas or even defining the problem and, if the situation requires it, start the process from the beginning.

1. Exploration

User research

I wanted to find out what people do in a situation in which their phone discharges while away from home: how they deal with this problem, whether their way of using the phone changes, and whether they feel discomfort with not being in touch with the world. I was also interested in their experience with sharing services (scooters, city bikes, cars for minutes). I conducted personal interviews with representatives of the X, Y, and Z generations.

I learned from the quantitative research that the focus should be on Generation Z and to a lesser extent on Generation Y. Only individual individuals from Generation X showed interest in the service.

The survey was great for gathering information quickly from a sample of my target audience, and the in-depth interviews allowed me to gain a deeper understanding of user behavior. From the interviews I found out, among others:

  • users are afraid that their phone will run out and lose contact with friends;
  • they fear that they will not be able to navigate in a foreign place;
  • will not have access to tickets;
  • they carry their power bank or ask to charge their phone e.g. in a bar;
  • users can change plans and go home to charge their phone;
  • they do not like to carry a heavy power bank with them permanently or forget to charge it;
  • they often use other sharing services (scooters, city bikes), but feel stressed about whether the rented vehicle has been properly returned.
Meet Michał

I used the results of research and interviews to create a fictional character, Michał. It helped me better understand how I could help him achieve his goal of having a charged phone and being free from sockets.

Meet Michał Kowalski, a 17-year-old enthusiast of games, scooters, and social media, who values independence and wants to be in constant contact with friends.

Empathy map

2. Definition

Purpose of brainstorming

To develop a brainstorming plan for a product development roadmap, I developed Point of View and How Might We based on an empathy map and Michael's persona.

How will Michał be able to borrow a power bank for the first time without having an account with us?

  1. Registration at the Kjosk station
  2. Connecting the card in the Kjosk station
  3. Onboarding a new user

How will Michał be able to check where the nearest Kjosk station is located and find out if there are free power banks in it?

  1. Map of Kjosk stations in the mobile application
  2. Number of charged and free power banks
  3. Reservation of a power bank for 15 minutes

How to guarantee Michał a free slot to hand over the power bank?

  1. Possibility to reserve a free slot to return the power bank
  2. Current loan status in the application
  3. Slot opening via NFC
  4. Feedback after returning the power bank

How to enable Michał to send an invitation to Kjosk? How to enable Kamil to register on the phone?

  1. Sending invitations to Kjosk via Social Media
  2. New user registration in the mobile application
  3. Onboarding in the mobile application
  4. Connecting the card in the mobile application
  5. Quick power bank rental from the mobile application
One of the brainstorms
Information architecture

After identifying a solid set of core features, I mapped the information architecture for both the desktop Kjosk and the mobile app. It allowed me to visualize the hierarchy of major and minor elements.

Information Architecture (mobile)
User flow

I have developed User Flow, which allows for a smooth and consistent user experience throughout the entire process, from registration, through card connection, power bank rental, navigation to the next Kjosk, power bank return, to feedback collection. I developed User flow both for the action starting in the mobile application and at the Kjosk station. I have prepared each of these flows for both new and returning users.

Below I present a small fragment of my work:

Fragment User Flow (Kjosk station, new user)

3. Ideation

By now, I have gathered enough information to move on to sketching wireframes. The huge and empty wall of our office turned out to be an ideal place to compose sketches and connect them with wool threads. It was an activity that brought me a lot of fun and at the same time allowed me to catch all the shortcomings of the previously developed flow in time. During this process, I tested all possible scenarios of using our service and most importantly the interaction between the mobile application and the Kjosk station.


4. Prototyping

At this stage, I prepared clickable prototypes with an average level of accuracy. Below I present the preliminary projects of several screens.

Power bank return

5. Validation

User tests

I conducted user tests of the mid-fidelity prototype on a mobile phone. I wanted to see how users would perform certain tasks when given a specific task to do. I was curious about which screen elements they would try to click and how long it would take for them to act. The purpose of this step was to identify points that could be improved in future iterations.

I tested, among others:

  1. Registration
  2. PIN reset
  3. Renting a power bank
  4. Power bank return
Similarity diagram

User testing has been extremely valuable. During them, I noticed a few shortcomings. I organized my findings in a similarity diagram to identify problems and potential solutions for future iterations.

6. User Interface


After making changes to the sketches, it's time to design. I wanted to keep a clean design and contrasting colors in line with the brand's brand book.

Makiety high-fidelity
App Motion

7. Feedback

The design process has no beginning or end. It consists of constantly adapting the product to the new needs of users and the changing reality. For the product to develop harmoniously, it is necessary to be in constant contact with the user. It is important to record user sessions with tools such as FullStory, observe opinions in stores, and create a space for a free discussion with users, within which they will be able to share with us their ideas for the development of Kjosk.

Measuring Success

In addition to the profitability index, indicators such as:

  • number of new accounts
  • number of rentals
  • refer friends inside the app
  • average rental time


Creating a comprehensive mobile application and application for Kjosk stations was certainly a large and difficult project. I had to develop an application that would meet the high expectations of the Z generation and at the same time take care of the harmonic flow between the mobile application and the Kjosk station. Thanks to surveys and interviews, I was able to discover that most people fear system issues when using other sharing services. Matching the existing aesthetic to match the brand book while still being comfortable with the visuals was also difficult, as I was free to make the app more distinctive, but I couldn't deviate too much from the original aesthetic. I am happy with the result. It was one of the most developmental projects I have participated in.

A fragment of the final flow of interaction between the mobile application and the Kjosk station


Product Owner: Krzysztof Adamski

UX Design: Jakub Nowak

UI Design: Jakub Nowak, Bartłomiej Balicki

illustration: Anna Kusz

Marketing: Agata Zborowska, Filip Styczyński, Jakub Goleniewski, Konrad Kocowski, Weronika Kwiatkowska, Grzegorz Żarnecki

Developers: Software Interactive, Paweł Karczewski, Ania Zavodian, Ewa Chwastek, Artur Śpiewak, Paula Śpiewak