Pausing runs: should be used for short periods of time only, for example if you need to wait to cross a road, stop and drink some water, or even if you just want to stretch for a few minutes before continuing your run.
Stopping runs: should be done when you want to stop running for a longer period of time. This applies whether your mission is complete and you want to stop running, or you’re only part-way through a mission and want to stop running. Missions are stopped by pressing the 'stop' button, and then confirming this via the 'are you sure' pop-up. You can then pick up where you left off, by returning to the mission screen and tapping 'Resume'.
For example:
A user wants to run to work in the morning, and then run home in the evening, but the journey is shorter than the shortest possible mission length.
In this instance the app should not be paused while at work. Pausing the run will keep the app running in the background, which will use up battery. There is also the risk that the operating system will shut down the app, due to it not being actively used, resulting in all progress being lost.
Instead the mission should be stopped on arriving at work, and resumed using the 'resume' button on the way home. Zombies, Run! has been designed to allow for missions to be stopped, and then resumed later. It's not necessary to complete missions all in one go, and there are no penalties for completing missions over multiple runs.