uMark is a free photo watermark software for adding visible watermarks on digital images. uMark can add text and image watermarks on multiple photos at once. Salient features of uMark are - 

• Text watermark
• Image watermark
• QR code watermark
• Shape watermark
• Batch processing - watermark 5o images at once
• Set watermark position, transparency and rotation
• Add border and shadow effects to images