Will Android kill a Service if I uncheck "Show notification" option on Settings? I was just wondering: will Android kill a Service (that uses persistent notification to keep itself alive) if I uncheck "Show notifications" on app settings?

I am running Lollipop 5.1.
Disabling notification would not terminate the life cycle of apps, nor would apps use persistent notification to keep themselves alive. Normally background operations would be done in the background, and notification provides a means to display the result back to the user via the main UI thread. Notification in this context refers to elements such as toasts (pop-up messages) and any icon the app might display in the status bar. In any case, the operation would have finished regardless of whether or not notification must be shown.