I’m sure you must have installed lots of applications from Cydia on your Jailbroken iPhone. Though sometime you might have installed some bugged Cydia app which might be restarting your Springboard or giving it Safe mode error. In this case best way is to uninstall such app which you have downloaded from Cydia.
Here is quick walk through on how you can uninstall Cydia applications which you have installed on your iPhone.
Go to Cydia and under manage click on packages.
Under Package, you will see list of all installed cydia app on your iPhone. Simply click on any of the app and click on modify. Select the option remove and within seconds that app will be removed from your iPhone.