After taking a shot using the Foodim camera, a "Save" and "Post" button appears top right of the next screen.
The Save button saves your image within the app in your Drafts, which you can find in you profile screen. The photo is not saved to your iPhone photos until it it is posted. You might take a bunch of shots of the same thing, and save them to choose the best one to post later. We designed it this way because we don't want to clog up your photo library. If you disagree and would prefer to have drafts saved to photos automatically, please email firstname.lastname@example.org with "Drafts to photos" as the subject to let us know. We'll take a poll and change it if the majority prefers this.