Whatever the final tally is, one thing is for sure: Amazon’s (s AMZN) Kindle Fire is a legitimate platform and will be driving app downloads for the tablet based on a modified version of Android(s goog) OS. Today, Read It Later (a service like TiVo (s tivo) for web content I recently profiled) came out and said iPhone and iPad, (s aapl) Android, Kindle Fire and Firefox extension.

This holiday it was the Kindle Fire—12.5% of all devices registered on Christmas day and an impressive 17% of new users on the day after Christmas were from the new Amazon device. As you can see below, the Kindle Fire is still quite a bit smaller than our Android and iPhone/iPad audiences (it’s also the only platform with no free version yet).

While some have claimed that Android users aren’t interested in paid or premium apps, 45% of Read It Later’s Pro users during the holidays came from Android, and 19% came from the Kindle Fire.

Those are some substantial gains for a new tablet that came to market just a few months ago. Nate Weiner, CEO and founder of Read It Later, tells me “the Fire had a huge presence in our holiday numbers (almost on par with the iPad).” His findings are in keeping with early results from other developers, as my colleague Ryan Kim reported earlier.

It’s clear the Kindle Fire will be a presence in the tablet landscape. Only yesterday, I was saying that app developers with limited resources need to support two flavors of Android: Samsung’s version and Amazon’s version. The early data from Read It Later only reinforces that.

P.S.: If you are seeing similar growth spurt because of Kindle, do get in touch and share details so I can include you in the post as well.