Enter Float, an iPhone reading app from Scribd launching today at Brainstorm Tech that aims to one-up different apps by offering many of the same features in one unified reading experience.

“There are a lot of companies in this mobile reading space, but what’s happening is it’s becoming really fragmented,” says CEO Trip Adler, who points to companies like Flipboard for browsing web content, Instapaper-like bookmarking services for saving items, and book-reading apps like Kindle. “We’re trying to tie all those features and bring all that content together into one app because there’s really no reason why you should be navigating with Pulse, saving those articles with Instapaper, and then reading books with something else.”

A “Favorites” screen acts as a landing page for users, letting them pick and choose which Web sites and blog posts to follow. Clicking on Fortune, for instance, presents users with a chronological list of the most recent stories from the Web site. Swipe a story’s headline with a finger to reveal a little more text about it. Don’t have time to read it now? Click and add the story to your “Reading List,” a timeline of bookmarked items natively stored on the device for later reading. (Fortune is one of 150 publications that is part of Float’s launch.)

The same rule applies to Facebook and Twitter feeds, though selectively. Float won’t pull all your status updates or tweets in the timeline — it only shows updates containing links to stories. So one tweet about a recent NPR story will show up in Float, while another tweet without a story link will be ignored.

All of that text, whether it’s a long web feature, a blog post, or a .pdf stored via Scribd, is reformatted without ads (for now, anyway — Scribd expects full-screen ads to launch in the fall), and dynamically re-sized to fit and wrap around on the small screen. (When users share stories with other Float users, they’ll also receive the same reformatted version, too.) And much like, say the Kindle or Nook e-readers, Float offers 10 reading styles with various fonts, sizes, and color backgrounds. Meanwhile, the “Library” will display all the stories you’ve read in the app, viewable by date, publisher or title, and the “Public Profile” tab takes you to your Float profile, which spells out your reading activities for other users to look at but can be set to private.

Initially, Float will launch for the iPhone and iPod Touch, with an iPad app due in the fall.

“We originally started with this idea of taking print documents and putting them on the Web,” says Adler. “So this is just going beyond that, expanding a little bit to help us realize the initial vision — to be a publishing and reading platform for everything.”

Update: At Scribd’s Fortune Brainstorm Tech demo this afternoon, Adler also discussed another revenue stream in development for Float: a universal paywall that will allow users to pay one fee to access premium content across all cooperating publications. He did not specify the fee or a firm timeline for release.