Agreed. There is PDF. That is what 'they' expect you to use. However, the PDF version that can be used with the Kindle3 is almost impossible to read without a microscope. When you zoom the article, it becomes too cumbersome.
This is one of the big downfalls of the Kindle, love it as much as I do.
Mobi has always been slow, since they publish whenever they feel good 'n darn ready. MMS has been somewhat better. Somewhat. That goes for the rest.
Since this isn't PBS and companies have to pay for the products that we expect to be free, there isn't much interest. Notice that Deseret Book's Gospellink hasn't done a thing since 2000 for ebooks, and that was proprietary to an obsolete ereader.
You are in the wilderness, my friend.
Then again, with the Kindle's limited ability to show newspapers and magazines on a reader sized screen (typically 3.5x4.75) the trade off is obvious: portable or readable.
The Kindle is difficult as a scripture reference finder either. Just not what it was designed for.
I have to plan what content will be used and make a bookmark ahead of time.
The big benefit is that I can loose or destroy 5 Kindles for every iPad that gets toasted. With a cost to benefit ratio like that, I bring a notepad.
The point is this: With an inexpensive reader we aren't likely to find any whizbang apps that will make a Kindle an iPad.