Along with the Flash 101 sale mentioned yesterday, DC and ComiXology have released a free Flash 101 digital booklet featuring origins, a rough timeline, and a collection of covers.
The timeline’s the most interesting part, to me.
It’s also got the two-page origins of Gorilla Grodd, the Trickster and the Pied Piper from Countdown to Infinite Crisis, and a similarly-styled two-page origin of Barry Allen by Scott Beatty, Howard Porter and Livesay that I think is new. None of the Flashes got profiled in 52, which was where the hero origins appeared, and the second page features the post-Rebirth costumes for Wally West, Iris West and Jesse Quick, as well as the Countdown-era costume for Jai West.