Here's how to block invites from apps on Facebook, including how to block invites from Circle app on Facebook.
If you are anything like me you will be tired of of getting unwanted Facebook app requests such as my current bete noir: "Circle - The local network". Here I'll show you how to block invites from specific apps on Facebook.
First up when you get a request from an application, you can simply select "Block Application" directly from the request. If you block an application such as Circle even once, it will not be able to send you any more requests. (See also: How to block people on Whatsapp.)
Open up Facebook via your web browser (rather than a mobile app). Look in the lefhand column. There should be an entry for 'Apps'. Click this. In the list that appears there should be an entry for 'Games'. Click this (if Games isn't there you need to use the search bar at the top of the page: type in 'App Center' and choose the result marked 'App Center - Facebook').
Once you've clicked the link you'll see a listing on the lefthand side. Near the bottom of that list will be an entry called 'Requests'. Click that. You'll see a list of all the apps to which you have been invited. Find the one for which you are sick of getting requests, and click the grey X next to the Try Now buton.
A yellow box will now appear. Click 'Block: App Name?' and you will never receive emails from that pesky app again. It really is that simple.
If you want to sort things out belt and braces you can also head over to your Requests page to 'Clear All' invitations to which you haven't yet responded.