Flighty is a fairly veteran application for iPhone and one that you probably know if you have to take flights frequently for whatever reason. Its developers have recently updated it to adapt to the new features of iOS 16, including updating flight information through a Live Activity.
But there is a small and brilliant detail of this update that is a whole lesson on how to take advantage of every loophole that both external conditions and the APIs of iOS itself give us. And it is that Flighty achieves what seems impossible: update the information of those flights even in airplane mode.
4KB is more than enough
Everyone’s asking how @FlightyApp‘s Airplane Mode works:
1. Plane WiFi allows iMessage
2. Guess what else uses that protocol? new Live Activities
3. So, send LA updates (max 4kb payload!) and have app load *that* data
Presto! The app updates via Live Activities 😎
— Ryan Jones (@rjonesy) November 21, 2022
It is one of the novelties of Flighty: displaying your updated flight information at all times, even when we have airplane mode active. In theory, this mode restricts almost all connectivity, but the developers have taken advantage of a loophole provided by the special Wi-Fi networks of some airlines.
Many American airplanes have a special Wi-Fi network with a very limited functionality: sending and receiving messages (it is a network designed to be used while keeping the airplane mode activated). Among those messages, Apple’s iMessage protocol is accepted… and Live Activities are capable of receiving data packets using that protocol.
So Flighty uses that permissiveness of limited aircraft networks to send and receive data packets up to 4 KB, with which you can update the Live Activities on the locked screen on iPhones. Perhaps this can serve as an idea for other applications that can do the same with their services.
You can download Flighty for free from the App Store, though the service requires a subscription to unlock all of its features (or a one-time perpetual license for $299.99).