iOS 4 makes it easy to leave apps without quitting, but what happens when you actually do want to terminate an application? Quitting applications can really help with older apps that have not been updated for iOS 4 "multitasking" and that do not properly return to the state they previously were in when resumed.
The most common type of app that fits this profile supplies Bonjour services that might not properly continue after resuming the application. Another app that reportedly has this issue is Gmail. TUAW reader Kefz writes, "Gmail does not work unless you force quit the mail application. If it is sitting in the multitasking task bar, [notifications aren't] automatically pushed to the phone...You'd have to open the mail app and have it check for new mail."
There's are two ways you can quit, according to Apple's documentation, although neither one is particularly obvious. Read on to learn what they are.