The Crawler

The crawler of the Fresh Reader runs as a client whose User-Agent is the following,

User-Agent: FreshReader/[version] (id: [Server ID];
  lang: en; http://www.freshreader.com/; [The number of] subscribers)

You can make the crawler run 15 minutes interval at minimum.
If you run the crawler within 15 minutes since the previous crawl, the crawler skips sites which it crawled within 15 minitues.