In case you missed the big announcement a couple weeks ago, Apple bought the incredible app Workflow, hired the small team of young developers who came up with the idea straight out of high school and made the app free. Right up front I’ll say I’m in the camp of this becoming a really great thing!1
In case you were living under a rock prior to that, Workflow is an automation app that brings the idea of Automator on the Mac to iOS, by way of 2 methods of app interoperability: x-callback-urls and iOS 8 Extensions.
X call what the what?
Apple built a function into the original iOS SDK for it’s own purposes of creating ease-of-use and clearly never anticipated or openly supported others co-opting it for other purposes. This function was the ability for identifiable link types to be handed-off to more appropriate apps by replacing their http protocol prefix with another unique protocol:
- a telephone number opens in the phone app by appending it with phone://
- an email link opens Mail app with a mail://
Back in 2011, developer Greg Pierce wrote a spec and documentation around the x-callback-url protocol, exploiting this part of the iOS SDK and wildly expanding it’s possibilities. It gradually garnered a fervent following by users and developers alike, and implementation surfaced in many apps (currently at least 124 mostly indispensable ones) allowing communication between them that previously didn’t exist. If you want to jump off here and dive into the tantalising possibilities this homegrown community has built check out Phillip Gruneich’s excellent library.
Enter iOS 8 Extensions
As much as x-callback-urls had an almost cultish following in the geek sector, the average Jane or Joe would understandibly roll their eyes if you asked them to contruct/deconstruct something like this:
Apple’s addition to iOS in version 8 of Share and Action extensions opened the world of inter-app communication to the masses with easy to comprehend buttons from a universal share sheet.
The downgrade was that these general only took information one way and only from Point A to Point B, whereas in the x-callback-url protocol you could essentially round-trip some data between limitless apps, picking up and dropping off new information along the journey.
Workflow obviously saw this opportunity to bridge the gap between these two worlds and expand it to a full blown app platform similar to the place Apple’s Automator has occupied on Mac OS for years.
With large candy coloured buttons, drag and drop action building and support of not only all the x-callback-url apps but also much more that don’t including most of Apple’s own apps.
But don’t hang around listening to me wax on about it…go download it for free and try some of the workflows out yourself. They range from the silly to the arcane to the incredibly useful you can’t imagine how you ever lived without it. And if you don’t find what you need, try building it yourself!