Last.fm iOS and Mac OS X SDK is a development kit created Kevin Renskers. Using the SDK, developers can work with blocks, use only KissXML as a dependency, return values in correct data types, hook catching methods, and cancel operations. This kit is actively developed and maintained and used in the official Last.fm Scrobbler app. Other apps using Last.fm include MetroLyrics and Radio.com. Requirements to develop include iOS 4 and Xcode 4.4 or higher, an API Key obtained at last.fm/api, and Kiss XML.
Sometimes it takes a little human intervention to make semantic applications easier to build. The Guardian newspaper has augmented its Open Platform API with unique identifiers for bands and books. In turn, the company has simplified the process of creating a mashup that uses multiple sources to focus on a single work, which may help its content spread farther.
Shoudio is an amusing iOS application made to tag places with audio snippets. These can be anything a user imagines, and a lot of fun could be had with this. For example, integrating this into Geocaching could be a lot of fun, allowing things like audio hints to help Geocachers find the cache. However, the developers of Shoudio didn't want it limited to just one platform, so they released a Shoudio API to allow clients for other platforms, and fun mashups.