Open Source Mobile Device Management?

H-MDM seems a nice product, and I understand that the company behind it needs to make money some way. But the limit of 3 clients(*) for the ‘open source’ version is very poor and practically unusable: I myself already own 3 mobile devices (2 smartphones and a tablet), so I can’t even ‘manage’ the devices for my family with it…
Or did I misunderstood the limitation for the opensource version? @h-mdm

(*)quote from the pricing page of H-MDM:

Cloud-based control panel limited to 3 devices