MTS Who Calls, developed in partnership with Kaspersky Lab, is a utility tool designed for Android that identifies incoming calls and alerts users about potential spam. The application checks incoming numbers against an extensive database, providing real-time information about the caller, helping users decide whether to answer or ignore the call. The free version offers key features such as identifying spam calls, allowing users to manually check numbers, and the ability to block unwanted calls. Users can also report spam numbers to contribute to the app's database.

The premium version enhances the experience by offering offline database access for number identification without an internet connection and removing advertisements. The subscription is available at a cost of 99 rubles per month, with a 14-day free trial for new users. MTS Who Calls efficiently categorizes calls with a color-coded system indicating the safety of the caller, ensuring users can avoid unwanted interruptions from spam and scam calls.