If you have a jailbroken iPhone, it’s very likely that you installed a lot of apps, tweaks and extensions that are now slowing down your device. Perhaps you noticed that it’s not as fast as it used to be, applications like Mail take a little longer to start up, you have to respring every 30 minutes to see an increment in speed. You know why? Because the stuff you install from Cydia eats up memory, a lot of memory sometimes. Winterboard, for example, can take a lot of unoccupied RAM if you start enabling dozens of themes and graphical modifications; same applies for other apps like Action Menu, Pro Switcher - all these things constantly run in the background (they are based on MobileSubstrate) and they are the reason why your iPhone is slowing down.
Fortunately, there are some tricks and tips you can follow to optimize your iPhone, free up a lot of memory without the need of respringing / rebooting and get a fast and stable device once again. Here’s how.