photoapplink Apple Open In...

Apple’s Open In… (left) and PhotoAppLink (right)

They’re two different APIs. One is called “Open In…”. The other is “PhotoAppLink”. They’re both great hooks in photo apps that lets you bypass saving images to the camera roll and open the image directly in another app.

It’s a great feature. I hope many more developers add it to their photo apps.

Both services get your image directly from one photo app to the next, bypassing the camera roll. When switching apps the user must save the edited image to the camera roll, quit the current app, launch the next and then load up the intermediate image before continuing to edit it. Not only does this cause version bloat in your camera roll, but repeated saving of a JPG can possibly add unwanted noise and artifacts to the image depending on the level of JPEG compression.

Both Open In… and PhotoAppLink allow you to simply select another compatible app in the save, share or export interface, which launches it and transfers the image from the previous app to the new, allowing you to immediately continue editing. Both greatly simplify the processing workflow. There are a few differences between the two. And, unfortunately, they don’t talk to each other.

Apple’s “Open In…”

Open In… is that great hook that allows you to send direct to Instagram.

PhotoAppLink is similar to Apple’s “Open in …” a feature you’ve also probably begun to see with recent app updates. Technically speaking, these apps are using the UIDocumentInteractionController. This is an iOS API provided by Apple that allows apps to register for certain file types that they can open. I’ve also seen the feature often in apps as “Send to Instagram”.

If the document types are provided in the app’s Info.plist — that would be .jpg or .png for most photo apps, other apps that recognize those document types will list the app in their “open in” choices.

Open in… is not necessarily a two-way path. While some Open in… photo apps both open and share images, some, like Instagram, Camera+ and Filterstorm only open. They’re incoming only.

Some of the photo apps that support Open in… on my iPhone are Camera+, MagicHour, Phonto, Cameramatic, FX PhotoStudio, 100 Cameras in One, and Filterstorm among others.


The developers of PhotoAppLink describe it thus:

When using an app with PhotoAppLink integration you can simply select another compatible app from its “Send to app” interface. That app is then launched and receives the image from your current app so that you can continue editing immediately. This avoids littering your camera roll with intermediate images and provides a much better user experience.

PhotoAppLink is an open-source library created by PocketPixels and CodeCrop and is being made available to developers of iOS photo apps. It’s now in a lot of popular photo apps. You can check which ones you have on your iPhone simply by pressing the “Send to Other Apps” button, if your app is PhotoAppLink enabled.

PhotoAppLink allows users to easily edit an image using multiple photo-editing apps by providing a mechanism to send an image from one app to the next. The feature is available immediately in these apps: Snap!, Color Splash, Simply B&W, PicTools, AutoStitch, TrueHDR, Juxtaposer, Click! and Photogene.

“Given the large number of high quality photography apps for iOS, users now have more ways than ever before to capture and edit images. Some of the best photography apps do one thing only but do it well. Thus, users often use multiple apps to process a single image. For example a user might take a picture using an HDR camera app, apply some effects using a second app, then crop it and add a nifty border in a third app, and finally share the image using the latest social-networking app.”

This short video demonstrates PhotoAppLink in action

PhotoAppLink apps automatically detect other compatible apps installed on the user’s device and present them in a user-friendly interface, which also offers a separate list of additional compatible apps the user doesn’t yet have. This makes it easy to find more apps that support this simplified workflow.

Hendrik Kueck, one of PhotoAppLink’s developers, says:

“Apple’s “Open in” dialog apparently also has a limitation of 10 or 12 apps, which would be a serious problem, especially because many non-photography apps also register themselves for image files.”

I asked Hendrik if there are any plans for the two APIs to ever communicate.

“Currently there is no good way to communicate with Apple’s UIDocumentInteractionController API. You can only point it to a file and ask it to show its dialog. That’s it. So, integrating it with PhotoAppLink in a sensible way currently isn’t feasible.”

Both are great features and a great time and space saver in the workflow.


PhotoAppLink was conceived and developed by PocketPixels and CodeCrop. It is implemented as an open-source library that is available on GitHub. The library is well documented and easy to integrate into existing apps.