Peek Cam allows you to set up your iPhone camera to take multiple pictures automatically. Set the length our the photo sessions you want. Set the exposure interval. Setup the camera wherever you want it and walk away. The camera will, on its own with no help from you, take pictures for you. The pictures will be saved in your Camera Roll folder.
Each photo session duration can be set from 24 hours to 1 sec. Each exposure time can also be set from 24 hours to 1 sec. You have great flexibility.
This is great for sleuthing or animal/bird photography.
If you are wifi connected and you have set up Cloud sharing with other Apple devices, then the captured pictures will automatically be distributed to all devices. You can monitor your progress remotely this way.