As per the Android document
Starting from Android 3.1, the system's package manager keeps track of applications that
are in a stopped state and provides a means of controlling their launch from background
processes and other applications.
Note that an application's stopped state is not the same as an Activity's stopped
state. The system manages those two stopped states separately.
Note that the system adds FLAG_EXCLUDE_STOPPED_PACKAGES to all broadcast intents. It
does this to prevent broadcasts from background services from inadvertently or unnecessarily
launching components of stoppped applications. A background service or application can
override this behavior by adding the FLAG_INCLUDE_STOPPED_PACKAGES flag to broadcast intents
that should be allowed to activate stopped applications.
On Force stop of app, Android just kill the process ID. No warnings, callbacks are given to service/activities. As per the Android document, When the app is killed there are chances that it calls onPause().
When I tried in my app, even onPause() was not called.
I think the only way is use to that intent flag and send it from another app as suggested by Chris.