Hi! I’m a highly experienced in VB Development and specialize in various social networking apps, including Facebook, and web-scrapping tools. So, this is maybe what you are looking for.
I have carefully read your requirements and would like to confirm some details.
1) What kind of app do you need? For example, it can be a desktop application with some UI, or a console server-side app (running 24/7 according to your purposes)?
2) How many accounts are you going to serve (please, notice than FB has some limits for simultaneous connections, as well as simultaneous mass messaging from 1 ip)?
3) How do you like to specify a post you are going to promote (by URL, or manually entering it in the app)?
4) Do you want to personalize your messages, for example "Hi {Firstname}, please don't forget to visit this event!" where {Firstname} will be replaced with a real recipient's name?
So, I'm ready to create a perfect app for your needs. Checkout my portfolio, I am well equipped to this kind of task, and I can handle it pretty well in a timely manner. Let me now if you are interested.
Mike