How do I view my friend's timelines with Feathers

Feathers is not a traditional Twitter client; it is only for writing tweets (albeit very special tweets that you cannot write with traditional Twitter clients). That said, you can use Feathers alongside your regular Twitter client (e.g., Tweetdeck, which is free, or Tweetie 2, etc.)

To summarize how to do it: When you exit Feathers, your message gets copied to the clipboard automatically so you can paste it into your regular Twitter client as a reply or a DM, etc.

For more detailed instructions on how to use Feathers with your regular Twitter client, check out this FAQ: How do I use Feathers with other apps?.