Open Radar

 
Currently every app if they wish to tweak photos before using it in their app context need to implement custom UI for modifying photo, when there are so many great apps providing really useful and entertaining photo extensions. But no 3rd party app can use it unlike with almost every other type of extension.
Photos.app has access to private framework PhotoEditUI allowing to initiate photo editing session for given PHAsset, but that relies on having special entitlements (if I'm not mistaken) so that editing framework can modify PHAssets in place
It would be great to open this functionality to other apps so that photo editing experience on the platform would become more unified and every app installed would only empower any other app that wishes to use 3rd part capabilities.
Probably it would be a good idea to provide option to specify white list of extensions app allows as part of image picking process (similar to how apps can white list 3rd party keyboards allowed to show up when given app is active, allowing additional layer of security)
Similar extensions should probably be able to specify whitelist of hosting apps, so that they can restrict apps allowed to use there editing capabilities to only their family of apps.

I tried to use private frameworks to see if it's possible to hack it together using PhotoEditUI, it seems possible up to the point where sandboxing kicks in, I will attach my sample code just in case along with video of desired result