Do you support HBO GO?
Yes, HBO GO is supported by the playmoTV. However it's worth noting that in order to access HBO GO, the user needs to have a subscription to HBO through participating television providers. The only way to get a subscription to HBO is by being a US resident (and already paying close to $100/month for cable).
If you don't have a cable provider login, then you might wanna check out HBO NOW or HBO Nordic. You can see the difference between these services in the blog post linked below.