I posted the message below under the "Troubleshooting" section, but I am not sure how many folks will see it there, so I decided to post it as a comment as well.
I purchased this app two hours ago. I figured that for $2.00, even if it turned out to be a crappy app, it would be no big loss.
So, after the installation, I launched the app, and then proceeded to provide my Facebook login data.
I logged in successfully to my Facebook account, and the app does in fact show my Facebook account name in the "Connected as" section of the app's window.
I left the "Export File Type" option at "xls".
Then I assumed that I was supposed to click on the "Get Data" button in order to begin importing the data from my Facebook account.
Well, that was one hour and fifty minutes ago, and the progress bar still says "Loading data..."
Now, I know that I have over 4,000 FB friends, and I suspected that it would take a while to import so much data into the app, however, something clearly appears to be wrong here.
I thought that perhaps there might be a problem because I am simultaneously logged into my Facebook account with the Firefox web browser. However, even after logging out of my FB account with Firefox, the Friends Export app is still just hanging with "Loading data..."
Is anyone getting the same results as me with the app hanging for so long?
I won't rate the app for now, just in case I am doing something wrong.