Does not Save the pic to roll

This app seems great till you try saving your work to Camera roll... Saves it as a black pic ... Whats the use of the app and its features if it doesnt save your work for you??? Is the app developer even checking the reviews and doing anything to fix the issue and how did Apple Inc. allow this app in their store without vetting the app and functioning of it?

Wake up Apple Inc about Dash of Color - Black & White, Colorful Photo Editor with Grayscale Effects, v3.6.1