Some app (such as Google photos) has no delete option when opening photo form outside such as screenshot's notification.
This small app will add a 'Delete' option to the share menu.
With Android 5.0 Lollipop's Project Volta, it can also auto clean old media files in SD-Card when charging.
(Not support 5.0-)
Free and open-source.
Source code:
https://github.com/heruoxin/share-to-delete