The Imagga Objective-C SDK by Imagga is available for download from the official site, that redirects to restunited library page. Image recognition, categorization, and tagging are some of the features that aim to be useful for application integration.
Magickly aims to make image manipulation possible as a simple web service. The Magickly API is very easy to use, and completely open source. It requires no API key, and allows a developer to use a lot of different image manipulations on any web-accessible image. Magickly is an open source, simplified version of the Aviary Effects API, which has a contest ending next week.
Facebook recently announced that its Instant Articles SDK will support both Google AMP and Apple News. Facebook will provide such support through an extension to its Facebook Instant Articles SDK. In addition to cross-platform support, Facebook will also support styling tools across both platforms.