Appcelerator's Titanium is one of the earliest, and still popular, platforms of the third kind. The latest product kit includes a cross-platform SDK with thousands of device-specific APIs, the Eclipse-based Titanium Studio IDE with built-in device simulators, and the option to host apps on Appcelerator's cloud servers. The SDK and IDE are free, while hosting and various levels of support are fee-based services.
For cloud-based mobile app development with no coding required, you might consider MobileFrame, which provides pre-built app templates you customize via a Web-based GUI designer, then deploy as either native or hybrid apps. Intended for enterprise-class app deployment, MobileFrame includes version and source control, database connectors, and an integrated test environment with device simulators. The platform features built-in MDM (mobile device management) capabilities, making it an attractive adjunct to BYOD.
In addition to vendor-provided native IDEs and cross-platform hybrid toolkits, a number of mobile development products target specific environments, such as a specific mobile OS or server-side hosting environment.
A good example is Google's J2ObjC Java-to-Objective C translator, which aims to let server-side Java developers move their non-UI code to Objective C that executes natively on an Apple device. Native Java is still prohibited by Apple in iOS, creating a significant barrier to Java-skilled app coders. Although Java developers must still learn Objective C for iOS graphical app components, legacy Java business logic can be preserved, saving the time and expense of maintaining two code trees.
CodeName One is a similar tool, but rather than translating Java to Objective C, it lets developers code almost entirely in Java, including UI code. The product's "lightweight architecture" provides seamless UI development across multiple platforms. Developers have the option to replace Java-coded widgets with native Objective C "heavyweight" versions when necessary for performance or to access low-level device features. And a GUI builder gives developers a full-featured drag-and-drop UI canvas.