If your photos are not getting saved to the camera roll on your iPhone, please double-check your "save photo" settings to make sure they're turned on. Here are instructions for adjusting your "save photo" settings.
Please note that filtered photos will only save to your camera roll after they've been uploaded to Instagram. Also, please be sure that you're using the latest version of the app, as we've fixed some bugs related to photo-saving in previous versions.
If your photos aren't saving after adjusting your save photo settings:
Check to make sure you have storage space on your device (open the Settings app, tap General > About and check the "Available" field)
Restart your phone (this will help ensure there are no memory issues causing photo saving to fail)
Instagram is a fast, beautiful, and fun way to share your photos with friends and family. Our service is not just a photo editing application, so iOS users do not have the ability to save filtered photos before sharing them.
You can find more information about adjusting your original and filtered photo saving settings here.