Briefly TELE2 is a self-service mobile app. Together with the launch of a new tariff line the company decided to rethink and remain the whole ecosystem that contains apps for iOS and Android and a website.With the help of the app, users can easily check or top up the account balance, choose a suitable plan, as well as to change SMS, minutes and GBs between TELE2 customers in the new plan. Challenge Nullgravity faced a few challenges. First of all, the Tele2 team were about to launch new tariff line in addition to existing ones. It would allow to share and exchange minutes into SMS, minutes for conversations or gigabytes and vice versa. But the problem was in their mobile app which didn’t support or reflect such kind of concept. And another even bigger problem was a short term for development. We had only a few months before the new plan was presented. Change everything "Change everything" is a new tariff plan that allows users to exchange their extra minutes, SMS or GB to the one they actually need. It was a brand new concept for the Kazakh market. However, in order not to disappoint more conservative customers, TELE2 had also keep old tariff plans as well. Inspired by Metro design language Because of complicated business processes, we couldn’t imagine the app interface of every user. Depending on the tariff plan, settings, profile details, current state of balance and many other things every user had to have a personalized interface of the home page with the relevant information. Results Our design team created a new design system where the users could manage both old and new tariffs with different settings. The matter was complicated by the fact that the client didn’t have digital guidelines. We developed a UX strategy, created a UI concept and covered complex functionality with Metro design language. In 4 month the brand new app was available in the App store. In this short term, we had also created a new website with users` account.