Thanks for reaching out to us!
To add a watermark image: Upload it to the Photo Basket (at the bottom of the editor) and drag it onto your image.
To add text: You can do this from the Text tab: Type your text in the top left box and click Add.
Once you’ve added your image or text, you can Fade it or choose an “Advanced Blend Mode” from the Properties dialog that appears.
You can do the same, except rather than the “Photo Basket” there’s a “Watermark” option on the menu bar.
Let us know if you have any further questions!
– Regards, The Ribbet Team