If you use Teamviewer turn on it's VPN ans if you are using it from outside your network it is very secure, or as secure as any VPN is.
I've tried many of these type of options during the past decade or so and for me Teamviewer has always been good and secure.
Many of the other ones need to be paid for before you get the benefits you get free with Teamviewer.
Logmein was the best before it went paid only.
Splashtop need to be paid for if you use it from outside your network, called Splashtop anywhere. Plus it was a lot slower than Teamviewer.