So I need to create a web app that does the following. So there is this website with chat, something like Wall, where people post messages. Well, what I need is to get a notification via email when a specific guy make a post. So when "Joe Doe" posts a message, I will immediately receive an email.

What I was thinking is this. An cloud based app, working 24/7 and checking the wall every 30 seconds for specific phrase. Let's say phrase is "Joe Doe". App is searching for that phrase and finds it. Now the count is 1. (CTRL+F). Now the last count in the database was 0, so it know it has to sends an email right away, because something has changed. And it goes like this.

Thats my logic behind it. The thing is that I have never developed a web app or chrome app. But that doesnt matter, because I know how to program, so Ill pick it up pretty fast. All I need to know is how everything works? What are the steps. The best way to do this? JavaScript? PHP? Chrome extension?

Is there already a solution for this? I couldnt found one.