This application is the first in Russia to combine the ecological, biological, and natural-scientific knowledge of freshwater fish from Northern Eurasia.

It is based on the mobile field guide to freshwater fish and anadrom fish of Northern Eurasia and covers 76 most prevalent species. The application allows the user to determine the species based on the appearance, habitats, reproduction time, and characteristics, feeding, way of life, differences from similar species, economic value, and conservation status. It is easy and fun to identify species using 16 determination morphological and ecological characteristics with 5-10 values in each of them.

The application includes a Guide, an Atlas, a Textbook, a Manual, a Systematic Tree (with class, family, and genus descriptions), and a Quiz.

The Guide contains the most important information for freshwater fish and anadrom fish from Northern Eurasia. The user can use it to determine the species and compare it with their images and descriptions in the Atlas.