iPhone jailbreakers may be familiar with the Backgrounder app, which allows running applications to continue running in the background. Up until now a task switcher such as Kirikae made it possible to switch between running apps.
Enter Multifl0w, a polished task switcher that works as if Apple itself had allowed and implemented multitasking. The slick interface shows previews of each running app and smoothly switches between everything running in the background.
Multifl0w version 1.1.1 is available from the Cydia Store or Rock Your Phone. The app is priced at $5.00 although it's free to use for a 10-day trial period from Rock Your iPhone. Backgrounder is a free download.
The more apps you leave running in the background, the faster your processor will eat up battery life. This is the most widely cited reason by Apple to not allow multitasking. Only specific apps are allowed to run in the background such as the iPod or phone apps.
To run an app in the background with Multifl0w and Backgrounder installed, just hold down the home button in an app until the "Backgrounding Enabled" message appears. Opening Multifl0w will show all of the apps running in the background, minus a blacklist.
The blacklist can include apps that run all the time such as the phone app. No reason to see this app in your Multifl0w screens.