With this program, you can take pictures of your screen (with the option of capturing the entire screen or just parts of it). Then, you can edit them with different tools, including brushes of different widths and with various text formats. In both cases, you can adjust the opacity as you wish.
After you've selected the part of the screen you want to take a picture of, just click the icon for web sharing and a link will be generated. You can then send that link to any of your contacts.
By default, the server configured to send the screenshots is the one that can be seen in the program developer's demo. However, if you want you can go to the configuration options and switch over to your own server.