Program to receive notifications in facebook groups

I'm Brazilian and my English is a little bad... I'll try to explain what I need... I work with buying and selling used electronics and most of the time I make these purchases in the facebook sales groups, I often lose the purchase of good items for not seeing such publications or arriving late and the person has already sold. I then need a program that I would login with my facebook account, select the groups I want to receive notifications and register keywords for this notification. For example, and I register the keyword "notebook" so every time there is a post with that word the program would notify I have no preference for a programming language, it can be done by the programmer anyway, the important thing is to work. It can be something that works only on the computer, it doesn't have to work on the cell phone.