KvantPhone is a secure mobile communication application developed by Arenim Group, designed for individual and business users who require encrypted voice calls and instant messaging. The application is available on iOS (App Store) and Android (Google Play) platforms and is positioned as a privacy-focused alternative to mainstream communication tools such as Skype, WhatsApp, and Viber. Key security characteristics include the use of post-quantum cryptography for protecting communications, continuous third-party security auditing, and an EU-based legal and vendor framework. KvantPhone offers individual subscription packages on a monthly, pay-as-you-go basis with no long-term commitment required. Packages are tiered based on the number of contacts a user wishes to include in their KvantPhone contact list. A 30-day free trial with full feature access is available. A separate business-oriented version (KvantPhone Pro) is also available, targeting larger organizations and government entities, with deployment features tailored to enterprise environments. The product includes a published Security White Paper outlining its security philosophy and architecture.