Remotely accessing Raspberry Pi from internet

Hello,

I plan to make a remote device using the raspberry pi and a few cameras that a user can login through the internet. I want the device to be plug and play, such that the user can plug in the cameras to the raspberry pi, power on the device, login to the home internet connection and after this the device can be accessed from the internet.

Most instructions that I have googled, suggest port forwarding, but this is not an option as it requires tweaking the router settings that would be an extra load on the user end.

I came across weaved IoT kit that enables remote connections to networked devices through various ports over the internet. However, this service requires commercial licensing and I want to start off with something free, if possible.

Please suggest some ways.

Thanks in advance.