This is not a duplicate of this question - Is there a way to force an app to remain running in the background no matter what? because it mention about Android ver 4 and also about lack of memory.
My question is is there a way to force a particular android apps for Android version below 4 to run in the background when the phone is sleeping? Also, I should be able to call those android apps that I specific to run in the background to come to the foreground for me to interact with.
The problem is that some apps, they stop working when the phone when to sleep (due to power saving). Some apps even prompt errors. However, I need them to run in the background. Also, I know that I can use 'Force close' to force a apps running in the background to stop but I just could not find a way to make a particular android apps to run in the background whenever I needed.