Control on Android 4.4.2

[Einfo Mail]

Hi,

My tablet is Android 4.4.2. I rooted it but unable to unlock its boot-loader. After rooting it …

How to control application permission, startup application and background running apps?

I tried some apps for all above controls but none of apps seems working find. And because of those apps, tablet sometimes stuck.

Please guide me these controls.

Regards
Einfo Mail