I'm sure this is old news to a a lot of you, but more and more people jump to android every day, and such people may have gotten misinformation along the way.
Task killers (services that clean your RAM) are absolutely unnecessary, and can actually reduce the performance of your phone. These RAM cleaners kill your phone's battery and performance by forcing apps out of your RAM, so that next time you use those apps they have to reload all over again. Android has come a long way as far as RAM, your phone will automatically kill off apps you aren't using if the extra RAM is needed, so you really shouldn't use any sort of cleaner.
Here's a great article on the subject if you want to learn more: http://www.howtogeek.com/127388/htg-explains-why-you-shouldnt-use-a-task-killer-on-android/