The overall rating reflects the current state of the app. It accounts for all app reviews but prioritizes the most recent ones.
It works for what it is... unless the buyer has a slow internet connection. In that case, the buyer can bypass the app because it's never shown to him. It's not the app's fault, though - you can always install it via code, to fix it. It doesn't provide an IP or Timestamp Signature for when the buyer. It's useful in terms of the buyer knowing the T&C, but it doesn't actually prove that he did (the acceptance is actually an "Additional Info" field on your order that can be edited) - if you're counting on this app to help you on stripe/paypal disputes, don't be very confident. However, for the price, it's great. PS: support is superfriendly and fast.