Mobile application for cryptocurrency exchange.

Challenge is the largest cryptocurrency exchange in Europe. It has 775,000 users. The platform works on the principle of a peer-to-peer bitcoin marketplace.


They turned to IntexSoft with a request to develop a mobile application for a crypto exchange. The company’s goal was to improve the UX on mobile devices. In addition, wanted to raise the importance of its brand through a corporate mobile application.


Team Composition

  • Project manager

  • 2 iOS developers

  • UX/UI designer

  • QA engineer


dev stages


IT experts


months project duration


The IntexSoft team divided the application development into 3 stages:


  1. Prototyping and design: our specialists conducted special workshops, where they learned about the client’s requirements, prepared and thoroughly processed in detail the screens’ prototypes and design.
  2. Mobile application development.
  3. Testing the application with real data.
UX/UI Design

The design process began with an analysis of the requirements and the data provided. An MVP was already developed and our team needed to adapt it for Android and add the possibility to notify users at the moment when the cryptocurrency rate was changed. In addition, the task was to design a quick access flow to buying/selling cryptocurrencies.


UX Process


A team of 2 project managers, 2 developers and a designer worked on the development process. 


We started with studying the requirements and working out the solutions using wireframing. After the sketches were ready, we discussed them with the customer explaining the pros and cons of each option. Here we focused mostly on the functional part.




Together with the client, we approved the version where the notification is displayed next to each cryptocurrency, and also there is an option to open an additional menu when swiping. Such a solution allowed us to save space for displaying more information,  while not overloading the interface and making it user-friendly.

During communication with the development team, we faced the problem: there was no native component for the sliding side menu. However, our team found a way out, implemented the component, and continued working on the UI.
Approved prototypes

Visual design – UI


To speed up and optimize the future work processes, we decided to use the components of certain elements in Figma. We also used native Android components to simplify and speed up the development. Company’s brand colors were used as primary ones. In particular, we used orange color to display active and clickable elements, as well as to highlight the active state of the alarm.


Since there was a lot of data in the app, and the elements with a small font were planned to be, we decided to use the standard Roboto font for the easy and quick perception of information.




The security issue was critical for the project. Our experts have carefully thought it out, developed and tested a high-level security system that prevents:


  1. Password theft;
  2. third party transactions;
  3. man-in-the-middle attack.


By providing secure access to data, our developers have achieved a high level of usability. To access the crypto exchange, the user needs to scan a QR code in a web app once. The code serves as a tool for the simple and quick transfer of keys and passwords as well as for connecting a mobile application to the crypto exchange web service. 


The keys to the application belong only to the use and provide data encryption and user authentication. If a third party takes a photo of a QR code, the connection will still be impossible.


The IntexSoft team used the AES protocol to establish a secure connection between the mobile application and the server. It’s impossible to decrypt data even when intercepting HTTPS protocols.


The dev team used a WebSocket connection to ensure a permanent connection between the server and the mobile device. It is necessary, in particular, in order to have the list of available offers updated.


Data protection on mobile devices is provided through biometrics: Touch ID and Face ID.

Production Stage

After implementation, the team delivered the application to the customer and it was published on Google Play. QA was carried out without our participation, but the customer came back to us with user feedback to fix some elements and add new functionality.

Methodology & communication

When working on the project, the classic Waterfall development model was used. It was the most suitable due to clearly defined budget and strict requirements.


During the project, the client could easily reach out to the IntexSoft team to resolve any issue. Our specialists organized video conferences with the client where they discussed possible changes and improvements.


  • User identification via QR code

    To access the crypto-exchange, you need to scan a QR code in a web app

  • Easy and secure authentication

    Via PIN code or Touch ID/Face ID (depending on the device)

  • Push notifications

    Notify the user about the currency rate reached the desired mark, and also in case of technical work or campaigns

  • Bidding

    Bidding for the purchase/sale of cryptocurrency

  • Offer submition

    Possibility to submit an offer for the purchase/sale of cryptocurrency

  • Auction

    Formation of a transaction for auction