When you tap the park lead button your current lead will be saved in it's current state ready to submit later.
The presence of a yellow triangle in the lead score box indicates that there are parked leads. Tap the lead count in the toolbar (on iPad) and select the middle column labeled 'Parked Leads'. In here you will see a list of all currently parked leads for the logged in user.
Tap on the lead you wish to load and continue capturing as normal. Be sure to submit the lead else it will remain in a Parked state.
Once all your parked leads have been submitted, the yellow triangle will disappear.
You can also manage your parked leads from the Zuant Cloud. Simply navigate to the lead grid for a particular event and select the 'P' icon. From here, you can submit or delete any parked leads. If no 'P' icon is visible in the toolbar, then no leads have been parked for your event.