What is the difference between the Task Manager and the Task Killer? What are the benefits of each? Do I need this app?
Task Killer is a free app that runs in your system tray and allows you to kill all running apps voluntarily instead of waiting for the system to reallocate what is needed.
Task Manager is a paid app that offers the same thing but also allows you to kill apps that Killer does not as well as system processes (not recommended), and also the ability to uninstall apps. What is cool about it is it also offers an "auto kill" widget that kills the apps you predefine with just a tap of the widget... This is the one I use!
Whether or not you need either of these apps depends on who you ask. Some will say neither of them is necessary but in my experience has greatly improved my battery performance. Most of the arguments I have heard against them references system performance meaning that memory and processor will be freed up automatically by the system as needed. Personally I do not kill any processes whatsoever and I have set up an "ignore list" of apps not to be killed.
If you are unsure about what to kill or not and you want to get used to them first to see how they behave, I would start with Task Killer till your comfortable and then later switch to MANAGER!
Best Of Luck!