Many times you share your copyrighted image on Internet with users Or you may send your image via email to friends etc then you must fear that someone else may take credit of your image.
In that case the best way is to add a Watermark on your image.There are lots of tool which adds watermark for you on your pics but some are paid and some are useless.
Image Water Marker is a free and portable app which will add watermark on almost all types of images.
Not only this you can customize the look of watermark like its transparency, Fonts, Rotation and its position.
It is very light and easy to use tool.All you need to do is just Open Image in it and play around with watermarks position and look which you want and then just save it.
The only requirement of this tool is Microsoft .Netframework,
You may use following link to download it:-