A highly recommended to avoid such executions in the background method is hibernate applications. Actually still in the background, but without consuming microprocessor, battery and RAM, but neither the kill.
This requires download Greenify, an application that can automatically hibernate apps we select until the return to open. Just do not hibernes necessary to synchronize data services or launch applications. The free version hibernates all downloaded apps and the payment can hibernate all system.
There are apps that are activated by simply booting the system and begin to consume resources since battery and turn on your phone. With BootManager can manage applications that run at startup, and disable Autorun Manager allows apps that start at the same time as the device.
All these tricks are used to prevent applications running in the background, but before applying note that if you block a basic application for the phone to work well is likely to have major problems and malfunction, so we recommend be very sure of what you do to avoid complications with your mobile.