I have a galaxy s2 skyrocket and it always slows after closing apps.?

[Android Core]

simple............... YOU HAVE LOW RAM.... your launcher (the homescreens you see) are sucking up alot of RAM so it can run..... either 1) you have alot on your screens, like WIDGETS (RAM suckers as we techs call them)... or 2) you are using the max number of home screens (usually 5 or 7 depending on the launcher you are using)... or 3... you have a live wallpaper on in conjection to #1 or #2......

reboot the phone... do a battery pull.... wait 3 minutes... work now????

If not, you have major RAM issues due to lack of phone maintenance...........your fix?????????

Buy an SD card..... Get App2SD and move apps to SD card. System Apps and apps that use system data cannot be moved.

Get One Click Cleaner. Run cache mode and wipe cache. Run Deep mode and wipe junk files left behind by uninstalled apps.

Get LookOut Mobile Security and run a antivirus/malware/spyware scan/removal.

Kill live wallpaper, use normal wall paper instead...

Kill social networking and email widgets. Use apps instead

Use 3 MAX homescreens... dont use 5-7 homescreens!!!!

Remember, the more you make Android do, the slower it becomes. Its not an Iphone where Apple controls the CPU/RAM (closed sourced system).

now reboot the phone, work now????

IF not, you have a ROM bug... do a master factory reset.... All data will be wiped... SD card will not be touched... work now??? if not, get a replacement phone due to defect