The Urban Airship InApp Messaging iOS Sample Code demonstrates how to use In-app messaging, aiming to improve an engagement strategy by providing messages that can be customized to be visually consistent with the rest of an app.
OpenChargeMap is a neat little service designed to help those with electric cars find places to charge up. With gas prices going the way they are, electrics are becoming a trendy alternative, and with the new Chevy Volt and Nissan Leaf offering good choices for the average consumer, more and more people are going electric. If you're one of those, however, there's always a hitch: finding a place to "fill up". Now you're covered and with the OpenChargeMap API you can integrate the service into other things.
Food-sharing mobile photo app Foodspotting had an API since day one. Of course, every mobile app has an API, at least if it needs to store or retrieve non-trivial data. Most of those interfaces stay hidden away, private APIs with only that single, internal audience. Foodspotting, on the other hand, signed Zagat as an early partner and now also has OpenTable, among others, using its Foodspotting API. The company is not exactly making it widely available for any developer, though the documentation is public, planting it in a vast grey area that's becoming increasingly common.
Google today debuted ML Kit, a new software developer kit with five core APIs that gives mobile developers the power to instantly add machine learning to their apps all through Firebase. If you're looking to add some serious computational smarts to your app, this is the tool you need.