Help finding the best App - FAQ with option to rank information of higher use / importance

Hi All,

I work as a Trainer and i am trying to find an app that allows me to post FAQs easily and as officers use the information they can click a button to say they have used it. The more clicks it gets the higher up the list it will rise so the most used  / useful information will drift to the top. I also need them to be able to make multiple clicks if they access the information more that once over the time it is posted. I want to create the content but then leave it to the app to do the sorting. Does such an app exist or can anyone suggest a way to achieve this?