Called "Free App of the Week," the section is only available to U.S. users.
Today, for instance, it's offering for free Cartoon Networks' Card Wars game, which usually costs $2.99.
Spotted by Android Police, the idea is not entirely new; in fact, Google ran a similar promotion last year, but it didn't stick.
According to VentureBeat, it was re-launched last week, with first app on offer being Ultimate Guitar Tabs & Chords, but hardly anyone noticed.
Google appears to have re-launched the Free App of the Week section without an announcement, so it's unclear what will happen after the current promotion is over.