Ipad vpn app

I need a VPN app for iPad. The app will be similar like VPN Express; [login to view URL] Here are the features needed: 1- User will be able to use the VPN free for 1 day. 2- There will be in app purchases. When in app purchase is done. The purchase will be forwarded to WHMCS system and account will be created for the user. Then user will be able to login using his account details. 3- There will be same auto install VPN feature like on VPN Express using mobile config. 4- When the account expires on WHMCS it will also expire on the app. This is a very simple app and it should not take much time. My maximum budget for this project is 300 USD. So please bid reasonably.