A free app for Android, by Two Sqaure Interactive.

Auto Sign & Stamp on Photo is a simple and easy-to-use application for adding a watermark on your photos. It is the perfect app to help you with your photo editing and copyright management. It offers a variety of watermarking options. The first step is to select a photo from your device’s gallery or take a picture using your phone’s camera. Then, you will need to choose a watermark template from the available ones. After that, you will need to select a font from the available ones and add some text to the image. You will also be able to add a signature, a logo, or other types of stamps.