Create a simple OpenVPN client for Windows and Mac

I have a small VPN with a simple custom VB.NET app, a couple of php scripts (App updates etc.) and OpenVPN servers. (Community) As mentioned, the current app is written in VB.NET (Screenshot included), uses some bad programming practices and is relatively unstable as well as not functioning on OS X which is what I want a client to do. Ideally I would like you to write a new client (using parts of old one if needed/relevant) which would function on both Windows and Mac, be reliable and efficient (no noticeable lag, UI flickering etc.)(native languages preferred, but not required) . As far as design goes I would prefer to have something close to material design with some animations (I do not think more than a couple will be needed). Current app gets server list and updates from PHP which is how I would like it to work due to firewall restrictions. I would also like you to look at the Server/Client VPN config to check if it is optimal for the application. Please contact me if you need further info or the app (binary/source).