Question: I have seen similar posts but couldn't find any answer..

Kindly advise whether its possible or not?

Answer: 
Applications can register a custom URL format, and then other applications can call that URL to trigger that application, pass it data, etc. Some of Apple's built-ins have URL formats that they've published, and some 3rd party apps have (and advertise) them too. If you're building more than one app, you can obviously customize your URL scheme to have your apps talk to each other more or less freely.
Apple restrict you to open 3rd party application, but you can open some application like safari,contacts,etc.,