Hello tson.
The task killer problem has more to do with stopping needed services than anything else. Those services will often be associated with apps or widgets or portions of the system that have to keep trying to restart once the task killer has stopped them. This can cause resource drain via "loops" of off and on again services.
RAM "boosters" are another challenge to the system altogether. A positive challenge, though, in some cases.
https://play.google.com/store/apps/details?id=com.rootuninstaller.rambooster&hl=en
Have a look at that app page.. not all RAM boosters are bad for the system. But I don't advise the use of task killers other than the task
managers in some newer Android devices stock.