App that notifies user when website is updated topic

How to create an android app that can notify user immediately if something on a website is updated.

Suppose I have a blogger blog like abcd.blogspot.com. So what i want is that whenever i post a new topic on my blog that topic notification should be pushed on to every android device that has my app installed. Please explain in detail if possible And I am not able to use php because its a blogger blog.