Yes, there are plenty of free watermarking apps that work offline and online. Some of them have a limit on how many images you can upload per day, while others offer only a half of the full range of their features in the free version. There are also apps that add their logo or words “Protected with…” to the watermarked images unless you buy a subscription or a license. The free version of our app has some minor limitations as well. However, if you need to watermark only a handful of images, it should be more than enough.