You need make 3 apps , 1 ANDROID , 1 IOS, 1 MACOSX to connect customers to server with vpn. Will be used an api for get customers details and get server list.
I will provide you with the current source code for windows and installer creating script, which is written in 100% C++/Qt. Windows source code can be used for mac without any major changes, because everything is written in Qt. At least 80% of the code can be reused.
Android front-end should be developed using Java, but the main functionalities of VPN can be achieved by C++ engine
For iOS, since apple excercises such a strict security policy, iOS app will require Network Extension API entitlement from Apple, which will take at least a few weeks to obtain, so better you have apple developer ID with this entitlement (Is important for me).
Use protoco Open VPN TCP/UDP, PPTP, SSL
Icon notifier change color when connected
All what have in windows app.
You need be flexible and don't charge me when we are running the project!
2 screenshot of the windows app
11 freelancers are bidding on average €1615 for this job
I will guarantee the perfect results firmly in the fastest time line. I value trust the most. Please suggest a suitable time for discussion. Thank you for your time and consideration. Sincerely