How does one connect a mobile device to a Netmaker network? There is no dedicated mobile app correct, so do you just use a Wireguard app or something? Or does the phone's native VPN handling support it? Do you have to manage the keys yourself?

use "external clients": https://docs.netmaker.org/external-clients.html

I did. Though I guess I missed this line upon my first reading.

Then, you can either download the configuration file directly or scan the QR code from your phone (assuming you have the WireGuard app installed). It will accept the configuration just as it would accept a typical WireGuard configuration file.

you have no keys to mange ... the config file you download is complete with keys

No I understand that, I just mean it's a manual process for each client you want to add, vs something like a login process where it is handled for you

No it does not