Apps of the Day : Facebook Photo Save for Android
https://gadgetsfreeak.blogspot.com/2013/07/apps-of-day-facebook-photo-for-android.html

After installing this application in your mobile, it is easy to store photo on your mobile in few easy steps.
- Open photo in facebook.
- Select to share it.
- Select Facebook Photo Save application to share with.
- It will give you option to store it in either phone or memory card.
And that's it...
Link to Download : Google Play Store Link
Cost : Free as of now.