Autostart iOS application

I am working on a VOIP application and need it to start automatically when the iPhone starts. Everything works 80% of the time. But 20% of the time when the application does not start. One test case is as follows:

• Open the application and enter something and save
• Reboot phone
• Check if the application works by double-clicking the home button, but DO NOT open the application.
• If the application is running, restart the phone again and see if the application appears in the background.

These scripts work most of the time, but not always. Other scenarios also fail. Can someone clarify if there is a way to launch the VOIP iOS app every time the phone starts?

Thank.