How to setup:
For VPN, first you need to setup DDNS
Open the router webpage, select Advanced tab then Advanced Setup, then Dynamic DNS.
Check the checkbox to use a dynamic DNS service, then enter a hostname and your email address, I used the Netgear DDNS, which is really noip.
Click apply to make the changes. You should get an email from noip to finish setup of your ddns account there. Follow the instructions to setup your account.
Now click VPN Service in Advanced Setup. Click the box to enable VPN service. I left all of the Advanced Configurations at their default values.
Click "For Smart Phone" to download "smart_phone.ovpn" . They also have for windows or for MACOSX, but I didn't try those.
Transfer the file to your phone. I used my password manager program to save and transfer, so the file would be secure. smart_phone.ovpn was added as an attachment to a note.
You might be able to open the router webpage on your phone, and navigate to the VPN service page, and download directly to your phone, but I didn't try that.
Android Setup
This was performed on a Samsung S6 that's on tmobile.
On my phone, open the password manager program, then opened the note with the ovpn file, then download the smart_phone.ovpn attachment into the phone.
Open the OpenVPN Connect app, then select "OVPN Profile (connect with .ovpn file)", and navigate to the directory where you downloaded the attachment. Select the smart_phone.ovpn file, then Import. Edit the title to what you want, then ADD.
Now click the little slider my your new profile, and it should connect. Test it to see if you're connected. Push the slider again to disconnect.
While you are disconnected, you can push the ">" to the right of your profile title, and then push SET CONNECT SHORTCUT. Set the title, and it will add a shortcut to your phone's screen. Then you can just push the shortcut icon to connect.
Iphone setup
Iphone 8 on ATT
On my iphone, open the password manager program, then view the note with the ovpn file, then select the smart_phone.ovpn attachment. Select Copy to OpenVPN Connect app, then OpenVPN will open. Select ADD. Edit the title to what you want, then ADD.
Now click the little slider my your new profile, and it should connect. Test it to see if you're connected. Push the slider again to disconnect.