Xpous' $9.99 iGenApps offers a code-free approach to building Web apps for both Android and iOS. Aimed at small businesses with simpler app complexity requirements and a limited budget, iGenApps enables businesses to construct Web-based apps right on a mobile device. The app, hosted on Xpous' servers, is distributed via an HTML link in email. Recipients simply click to add the link as a home page icon.
Adobe's free PhoneGap exemplifies the WebKit strategy, letting you code your app once on the server side, then deliver to multiple mobile OS targets quickly and easily. PhoneGap augments the basic shell with plug-ins that emulate various native interface widgets, giving users even more of a native user experience.
Rather than delivering an identical Web-ish interface on all device types, as pure Web apps do, hybrid apps can provide a different user experience for each mobile OS: Android idioms on a Kindle Fire, iOS behavior on an iPad, Metro accoutrements for a Windows phone.
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.