ANONguard anonymises you Internet access by hiding your IP address. ANONguard is based on the AN.ON technology (https://anon.inf.tu-dresden.de/index_en.html).
Mainly bug fixes and performance improvements. Due to some changes to the way the App settings are stored it might be possible, that no connection to the anonymity service is possible after update from a much older version. Please reinstall the app in this case (or delete the app settings using your phone's app manager).