When Appareo, Sporty’s and ForeFlight launched Stratus, an all-new free-weather ADS-B receiver for the iPad at Sun ‘n Fun, we couldn’t wait to review it. As it turned out, we didn’t have long to wait.

For at least two decades, business aircraft pilots have been promised that someday they would be able to download weather graphics directly onto cockpit displays. The availability of uplinked weather ...