Text Tool: Click on this icon and the window below appears on the screen.
Here you can add text, select the font, size, stroke color and fill color. You can also apply the desired Stroke width, alpha and Fill alpha using the sliders.. As you make the changes these are displayed in the preview window. Addtional text options include Bold, Italic, Underline and Strikethrough.
Once you have completed modifying your text click OK and your text is displayed on the image. You will be able to move the text by holding down your left-mouse button and dragging it to where you like. If you would like to rotate the text hold down the right-mouse button and move the cursor and you will see the text rotate.