CSN Tests is an Android application developed by Ēriks Sarguns. It falls under the category of Education & Reference, and it is free to download. The app is designed to help individuals master the traffic regulations of the Republic of Latvia by taking tests.

With almost 1000 questions available, the app covers the same topics as those found in the study materials. The application is small in size, as it does not contain any question definitions. Upon launching the app for the first time, it will download and save the necessary data files (approximately 40 Mb) to the SD card, making it available offline.

Overall, CSN Tests is a useful app for anyone preparing for the CSDD "B" category exam in Latvia. It is easy to use and provides a variety of questions to test your knowledge of the traffic regulations.