De hade ju inte riktigt rätt i det som skrevs.. Den kräver inte Backgrounder.
"Using Multifl0w without Backgrounder on iOS4 will function like Apple's switcher, apps stay "open" in memory (although not actually running). Using Multifl0w without Backgrounder on 3.1.x is not advised, because apps will be closed as soon as they are exited. However, Multifl0w does not force Backgrounder to be installed on any OS version for maximum flexibility."
För övrigt kan jag säga att Multifl0w är hur Apple skulle ha gjort, fungerar grymt på iPhone 4!