Under the direction of ecsec GmbH, an Open Source implementation of the eCard-API-Framework (BSI TR-03112) was developed in the „Open eCard“ project. Based on this framework, the so-called "Open eCard App" was developed and the Federal Office for Information Security (Bundesamt für Sicherheit in der Informationstechnik, BSI) certified it under the certificate no. BSI-K-TR-0192-2015 as "eID-Client" according to BSI TR-03124. This eID-Client, which source code can be analysed and which is therefore particularly trustworthy, implements the international standard ISO/IEC 24727 and enables the use of the various electronic ID cards in the SkIDentity system. The comprehensive evaluation and certification ensures the secure and smooth interaction with other services and components in the area of electronic identity cards.