Marker and Highlighter are both free hand tools. They are both similar in function. I would like the marker to be a freehand tool to underline or circle a concept in PDF or Image. I STRONGLY RECOMMEND that the highlighter tool should not be a free hand tool. Rather based on OCR in image and PDF we should be able to select certain text and highlight it. I would look clean. Similar to Adobe Reader and other softwares. Please let me know if this sounds interesting. And can the team think on incorporating the change.