Is there any necessity to use one SSL certificate for enabling Apple push notification for iOS applications.If yes then what is the use of including it. Any suggestions will be really helpful.
SSL certificate helps to secure data travelling between two ends (i.e. browser and server). So nobody can intercept the confidential data like, email, password, address, SSN, etc. entered by users.
Apple has already declared deadline for all apps in App Store must switch to App Transport Security by January 1, 2017. Check this article for more details: https://techcrunch.com/2016/06/14/apple-will-require-https-connections-for-ios-apps-by-the-end-of-2016/
In addition to use features like, geolocation, Push Notification, getUserMedia(), HTTP/2; you must have HTTPs for Google Chrome. Have a look at this post for the requirements on HTTPs in 2017.