What OS are you running on the Raspberry Pi? If you are using the latest Raspbian (desktop, not lite) then it has a VNC server already in it - all you need to do is turn it on on the Raspbian configuration tool.
Once that is working, you should be able to access it from any VNC client (provided you have the necessary access through firewalls etc.). Just be aware that the intervention network can make it virtually unusable if the bandwidth is not big enough.
Having said all that, what sort of control do you really need? I've used SSH to connect from my iPad to my RPi (which *is* running Raspbian Lite, i.e. no GUI) and it allows me to control everything I could from the terminal connected directly to it with reasonable speeds.
Susan