GoSupportNow is described as 'Remote support service for PC & Mac. GUARANTEED CONNECTION. Built-in web meeting for collaborative support & training with up to 10 parties. $19.95/month' and is a Remote Desktop tool in the network & admin category. There are more than 50 alternatives to GoSupportNow for a variety of platforms, including Windows, Linux, Mac, Android and iPhone. The best alternative is TeamViewer. It's not free, so if you're looking for a free alternative, you could try Remmina or DWService. Other great apps like GoSupportNow are AnyDesk, mRemoteNG, TightVNC and NoMachine.
Remmina is a remote desktop client written in GTK+. Remmina primarily targets system administrators and travelers that need to work with computers remotely in front of either large monitors or tiny netbooks.
DWService is an half (only the client/agent) open source project which offers a service that allows access to remote systems (Windows, Mac, Linux, Raspberry...) using a standard web browser - without any component required on the client side.
TightVNC is a free remote desktop application. With TightVNC, you can see the desktop of a remote machine and control it with your local mouse and keyboard, just like you would do it sitting in the front of that computer.
Support customers on a remote computer easily through web-based, on-demand remote support sessions. Set up unattended remote access and manage remote PCs, laptops, mobile devices, and servers effortlessly.