Both the iPhone and the latest Android app allow you to view, pause, resume, and activate your existing action plans. All action plan activity is performed from the lead detail screen. These screens will display lists of currently or previously activated action plans for a particular lead.
Pausing and resuming plans
Tapping on the action plans that are displayed from with a lead's details will allow you to pause or resume them (if they have not completed already).
On iPhone simply navigate to the Action Plans tab on the lead detail screen, then tap "Add Action Plan". On Android tap on the large circular button and tap the exposed "Action Plan" button.