facebook messaging statistics. (Anonymized) sample output:

You can use the version hosted at http://tehdog.github.io/fbstats/ As the API from facebook is still in beta, you will need to be facebook developer and create an "app" for this to work.

1. Go to https://developers.facebook.com/ and become a developer
2. Create a new app
   
3. Settings -> Add Platform -> Website. Site URL: http://github.io/
4. App Domains: github.io
5. It should look like this:
   
6. Go to http://tehdog.github.io/fbstats/ and put in your app id. Voilà!

The code is really ugly and probably hard to understand, if you have questions just ask.

The already downloaded message timestamps (Statistics.threads) will be stored locally, so they are cached when the page is refreshed.