In the world of photography and even blogging, image stealing is a regular occurrence.

Photojournalism is all the rage these days and with the explosion of social sharing sites like Instagram and Pinterest, it can be slightly impossible to keep track of who else might be using your images. (There is a widespread belief online that once a photograph is posted then anyone is free to use it. I once had a client tell me that all of the images he found via Google were free for the taking. Um, no.)

I recently came across an iPhone app called Marksta, the brainchild of multimedia photojournalist John D McHugh, which lets users place a watermark on their mobile photos before sharing them on  media sites.

What I like about this app is that it allows you to customize your watermark in a few ways  by changing the font, size, color and even adding a drop shadow. And happily it also allows you to arrange the watermark so that it compliments the photo rather than obscuring it. You can add a copyright symbol, hashtag or even optimize for twitter.

Cost: $1.99.

Marksta is available in the App Store.