The overall rating reflects the current state of the app. It accounts for all app reviews but prioritizes the most recent ones.
Their proprietary counter is giving false numbers on the amount of shares. This can be shown from the website replays (I'm not seeing even half of the people clicking the button). Other than that, the button works just fine and does its job.
Thanks for your review, apologies for any share count error you have encountered. We'd be happy to look into this more deeply, please send us an email at firstname.lastname@example.org and we'll try to reproduce your issue and get to the bottom of it.