Gimp has a very simple but highly advanced TEXT tool.
If you are very new to Gimp, you can start placing text over any image just by clicking on the text tool and typing.
You can change its font, size, color, etc with the tool options.
If you want to select the whole text, use the color selection tool and click on text. After that, you can delete it from the background, recolor in different colors, and do many other operations.
Lok at the Gimp screenshot below:
