I have a mobile html page which contains images. I want to create a button or a link which is used for a download of an image. The image should then be saved to the users mobile
Somebody seems to have answered this already,
It's not yet fully supported http://caniuse.com/#feat=download, but you can use with modernizr
http://modernizr.com/download/#-a_download (under Non-core detects) to support all browsers.
Have not tested, but should work in mobiles as well.
I would add that, as a server side solution, you could also add Response Headers to your download endpoint by