Is a start then where to start here? That is, some folk that ask your question don't know what they asked for. That is, there is no web mechanism today to send you alerts when such changes so your APP (let's call this an APP for now) will have to check each site on a schedule you set. Now if you check it every second well the web site may notice and block your access. But I'm sure you knew these issues.
So with that out of the way, write a bit more about your app and get some programmers on it. If it's worth doing, I'm sure you'll pay for it.
Bob

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