With MapTiler Desktop, you can prepare a custom map for Locus mobile app. You can add to Locus USGS topo maps for hiking, old Soviet maps, drone imagery, old historical map or any other map.
It works on Locus on Android in both Free and Pro version.
Prepare your map
First, download and process your image by MapTiler Desktop.
During rendering, select the MBTiles format.
When rendering is ready, upload your .mbtiles file to your mobile.
Turn on your map in Locus
On your mobile phone, open Locus application.
In Locus, click on hamburger menu in the top left corner.
Switch to Offline in the top menu and click on the Plus button in the bottom right corner.
Select External maps from the submenu.
Click on the Plus button in the bottom right corner.
Browse your mobile for the .mbtiles file.
When found, add it. Now click on it, if your map is outside currently view area, you will get a pop-up: "Selected map out of current view. Center?" Click Yes. Now your map is ready to be used offline in the Locus mobile application for any outdoor activity.