Syncler works on Android TV (Fire TV, Nvidia Sheild too), phones, tablets.
Syncler - One app to sync them all. Introducing the best syncing app there is.
A paid option is available if required.
You need to install the "Syncler Installer" first which will then install the main and separate "Syncler" app.
You will then need to add a package - in the app settings > Provider Packages (at the bottom) install Kosmos or Express and you will be directed to the Syncler site to enter a code via https://syncler.net/install. Follow the instructions.
You can get the latest package URLs from the following web page https://shorturl.at/flBJY for Kosmos or Express.