If the version string in the mod says: compatible with 1.0 only, it doesn't show up in the mod manager of the game if you are on 1.1. the only way is either to manually download and to enable it after saving it in the mod folder, or you need to downgrade factorio to 1.0, install it via mod manager, upgrade to 1.1 and then keep it selected.
Easy fix: just change the line in info.json of the mod to "factorio_version": "1.1" and push a new version to the mod main page here. Then others who play on 1.1 might find and use it.