The overall rating reflects the current state of the app. It accounts for all app reviews but prioritizes the most recent ones.
The Youtube Society
I used this app to show a simple message on top of my website. The title describes perfectly what it is. SIMPLE. This is great for any new Shopify users. It doesn't really have too much going on. The only thing is that they should explain what is what when you first download the app. But other than that, it's a good starting point.