There's an underlying assumption in most of the thinkpieces spawned by emergent speedreading apps: that you'll be using them to catch up on the massive assortment of thinkpieces you don't have the time to ingest.
Velocity, Spritz (which is actually proprietary tech, not yet an "app"), and the 2006 web-based spreeder all facilitate speedreading via a method known as Rapid Serial Visual Presentation (RSVP). RSVP, as spreeder marketing copy explains, focuses on "silencing subvocalization" (which, in turn, is defined in Velocity's copy as your "inner voice"). spreeder and Velocity accomplish this by basically flashing words at you really fast. Spritz adds its own "Optimal Recognition Point," often a vowel, in red so as to excise time-consuming eye movements. In each case, the eye is presented here as the blood-brain barrier, with the text ever trying to pass through it more efficiently. This is a rather unique method for dealing with the stresses of the war-like domain of the longread; now you can "read" everything.