could you help me to deal with this watermark?

I design a logo for my new company website, I do not buy one tool, because there are so many free maker and trial, so I download a suitable logo maker consistent with my website style, which is a free trial version, I like it very much, but there is a watermark “sothink logo maker” at the back of my designed logo. Who once used this tool? is there any method to remove such watermark? Please help. the site is

well , i checked the link in your post , the only solution i can say to you , it to buy it or to use any free alternative tool instead of it .