Here is something which took me longer than it should have to figure out how to do: filter a Kindle search result to show only books which are available on Kindle Unlimited. Ready?
On Your Computer
1) Go to Amazon.com and do a search for a Kindle book.
2) In the sidebar, a little checkbox will pop up for ‘Kindle Unlimited Eligible.’
3) Tick it, and voila!
On Your eInk Kindle
1) Go to the ‘Shop in Kindle Store’ menu. The Kindle Store will open up.
2) Do a search as you normally would.
3) Under the ‘refine’ command, there will be a ‘Kindle Unlimited’ filter
There you go! Happy reading!