If you are looking for Soviet maps for desktop use rather than mobile, you can explore archives such as:
Soviet Military Maps Pro is an Android mapping application that provides access to a massive archive of topographical maps created by the during the Cold War. These maps are renowned for their incredible level of detail, covering not just the Soviet Union but the entire globe, including remote and underdeveloped areas [1]. Download Soviet Military Maps Pro zip
Identifying old trails or terrain features. If you are looking for Soviet maps for