NO APPS WILL OPEN ON JAILBROKEN IPHONE?

I installed Flex 2 from Cydia and my friend installed a hack called Instagram: Instagram Followers and now every app won't open and I tried deleting Flex but it they won't open.

Reset/Reboot your iPhone all your apps and stuff will go- seems like your only option…

Be careful installing apps like Instagram Followers as they tend to be malicious and can steal your account or ruin your phone. Only install apps from trusted sources. Uninstall All non-mandatory jailbreak apps and tweaks, this will give you a fresh jailbreak, restart your phone and it should work. You can then reinstall any payed apps by logging in and it will be in your purchases.

Hold power button for 3 seconds, without letting go, press home button and hold both until screen goes black. From there let go of home button BUT keep holding the power button until the Apple logo shows and just wait until your device boots up again.