I have a Galaxy S2 from Virgin Mobile. My home network is Windows Server 2012. I'm using RAS to connect to my home network from other locations on a Windows 8 laptop. I have several SharePoint sites within my home network that I'd like to test from my phone. Most of the software I find on Google Play when searching VPN is to mask my browsing history or act as a proxy server. I'd like to VPN into my network from my phone.
I also have a Netgear Nighthawk R7000 wi-fi router, but I'd rather only use that if it's my only option. Doing some searches seems to say that Android is not supported for that router anyway.
What free or paid software can I use that doesn't require my phone being rooted?
If my only option is to root, what's the best ROM for my phone?
What free or paid software is best for a rooted phone?