To take a photo on your iPhone without physically tapping the shutter button, you can set a timer to take it after a brief ...
When you want to take a group photo, but no stranger is around to take one for you (or you don't want to hand them your expensive new smartphone), you can use your iPhone's camera timer to get the job ...
You can add a filter or lens to your Snaps, but the process is quite different, depending on the effect you want to use.