KCharSelect is a useful tool to find and copy Unicode characters. I find it useful to use Unicode characters and emoji in emails and articles. There are Unicode characters for pretty much every type of object or expression now. But finding the Unicode character is a pain.
KCharSelect makes searching for a Unicode character easy because it allows you to search based on the Unicode character description.
$ sudo apt install kcharselect
Open KCharSelect dialog. Type a partial string describing the Unicode character you want to find. It shows all the Unicode characters who have that string in their description. You can pick the one you want and copy it.
You can choose a Unicode character and also bookmark it. Bookmarked characters appear in the Bookmark menu for easy picking in the future.