We purchased the MyQ 828LM Internet Gateway (lists for $60) and use it with our two garage door openers.
From a smartphone, we can open/close either garage door from anywhere (not just in close proximity to the openers).
I wish Tesla would provide support for the gateway as an alternative to Homelink, because the MyQ gateway knows the current status of the garage door - if is in the open or closed position, while Homelink has no way to determine if the door is open or closed.
When my wife (in her X) and I (in my S) arrive or leave at the same time, unless we override the Tesla's automatic door opening/closing, we'll either leave with the garage door open, or the second vehicle will drive towards the garage with the door closing...