Truphone

Cellnetrix GmbH is a research and development company based in Hamburg, Germany, with an additional office in Russia. Founded in 2006, it specializes in developing software solutions aimed at enhancing the reliability and security of wireless mobility and Internet services. The company focuses on operating system development for universal subscriber identity modules (USIM) utilized across various mobile networks, including GSM, UMTS, and CDMA, as well as WLAN. Cellnetrix also provides secure mobile applications and comprehensive Over-the-Air post-issuance management services for SIM and R-UIM cards through its proprietary platform. Its software solutions adhere to industry standards established by organizations such as the Open Mobile Alliance and 3GPP, utilizing the widely recognized Java programming language. The company's clients include notable telecommunications firms, contributing to its reputation in the industry. As of December 31, 2017, Cellnetrix operates as a subsidiary of Truphone Limited.

CoSwitched is democratizing devices’ access to the Internet and at the same time enabling rich voice machine communications. CoSwitched is an Internet of Things Mobile Virtual Network Operator. CoSwitched - Machines also have a voice!

S4T Plc does not have significant operations. It intends to explore for new technologies and market opportunities. Previously, the company was engaged in the provision of access to a low cost mobile phone solution to travelers. It was formerly known as SIM4Travel Holdings plc and changed its name to S4T Plc in November 2008. The company is based in London, the United Kingdom. S4T Plc is a subsidiary of Software Cellular Network Limited.