Amazon announced today that the Kindle would be opening up for development of third-party apps. It’s getting everything too, not just weather widgets and email browsers. You want games? You got ’em. Though, you’ll probably hate most of them on that e-ink display.

Really, this has to be a future-proofing move for Amazon. I can’t imagine many developers will be clamoring to get apps on the device, especially with the limitations in place. Free apps have to be less than 1MB and use less than 100KB of data per month. Paid apps are under the same usage limit but can be as large as 100MB, though anything over 10MB has to be downloaded via USB.

It’s hard to imagine the kind of apps that could be successful on a Kindle. The screen refresh works for ebooks, but imagine trying to play a game. It’s just not going to work out. The real benefit, it seems, will be to get developers involved before the release of some sort of color Kindle with a real screen. Until then, I’m pretty sure the “apps” will just be ebooks that serve specific markets.

Last week we reported on a pretty little ereader for the iPhone that didn’t make Apple’s crazy approval process because it allowed access to the Kama Sutra. It sounds like Apple’s smarter thinking prevailed, and Eucalyptus has been reinstated at the original $10 price tag.

Though it’s tough to say what really made the difference, I’d like to think rampant posts about the ridiculous rejection brought it to Apple’s attention, at which point they actually thought, instead of just mashing the ‘declined’ stamp on seeing the words ‘Kama Sutra.’

As for the app, I’m not sure I’d spend $10 to read public domain books (read, old) on the go. It’s a nice model, though, and hopefully something others can look at to make future apps with some added functionality.