AnyDesk is the world's fastest most comfortable remote desktop application. Access all your programs, documents and files from anywhere, without having to entrust your data to a cloud service. All you need to do to get started is to download and launch the 1.1MB program file. No installation or (network-)configuration required.
Excellent and secure remote control program that is nearly as good as TeamViewer. For Free Non-Commercial use it does not restrict you like TeamViewer. With Teamviewer, if they suspect "commercial use" they will prevent you from using their program. In addition, Teamviewer is ridiculously expensive for commercial use. AnyDesk is reasonably priced and offers yearly subscriptions as well.
Not as mature as Teamviewer but works nearly as well.
I needed a support tool that was (a) free, and (b) easy for my 85 year old mother to install on her end, 2000 miles away. It worked great. I was able to log in and fix her problem. Reviews here on Download helped greatly.