If your photos are not getting saved to your device's camera roll after you have posted them on Foodim, the chances are that you denied access to your camera roll when you signed up to Foodim. Here's how to fix that:

1. Go to iPhone > Settings 

2. Scroll down and Tap on Foodim in the list of apps

3. Make sure you have Photos set to allow "Read and Write". Your photos will now be saved to your camera roll when you post them on Foodim. 

You will also be able to import photos from your camera roll and post them on the network.

Screen shot attached for reference