Appcelerator Cloud Services
Appcelerator Cloud Services (ACS) provides around 20 prebuilt services that are used in most web or mobile applications today (Status, Check-ins, Chat, Photos, and a lot more). They provide an SDK that is already embedded into the Titanium framework, and they also provide dedicated SDKs for iOS (to use with Xcode) as well as for Android. But ACS is not only targeted at mobile applications; any application can pretty much interact with ACS using a REST API that they provide.
Each of these SDKs is detailed in the official Titanium documentation at http://docs.appcelerator.com/cloud/latest/.