There have been several jailbreak tweaks over the years that have attempted to revolutionize the concept of multitasking in iOS. Few, if any, have come as close as ProWidgets, a new widget framework that’s available in Cydia now.
I say close because I don’t think ProWidgets solves a better way to multitask on the iPhone and iPad. However, it is a valiant effort that allows other developers to create third-party widgets that live outside of the traditional app experience.