This app lets you take photos of an item or scan its barcode and then presents the lowest price from Skroutz making use of its API. App uploads photo to Google Cloud Vision API to detect and understand what presents in the photo recognises the text and then search for this item.
Still not getting best-expected results, mainly from Skroutz, still developing.
Current state of the app can be found here
https://drive.google.com/open?id=0BxHY5QjZ1t84ZjZ1VWpaWno1OW8