The fastest way to check in lots of items is to batch them. Batching helps items process faster and, if your property uses notifications, ensures that notifications get sent to recipients in a timely manner.
Step One: To batch items, tap "Check-in" once
Step Two: Capture as many images as there are items. Do not tap "Finish Batch" after capturing each image
It's unnecessary to organize batches by a person's name or by department. Capture all the items you receive, regardless who they're for, in a single batch for best results.