It's an extremely easy way to make a custom computer lesson for your students. Any language, Any topic. Students can see a line where letters used to be. You can also give a hint. Hints will appear in the field above the student's window.
Students type the words they think are in the answer.
If they are right, the word appears. Your hint provides the goal, the lines help the student to think about how to achieve the goal, and the program provides instant feedback. New Deletion will clear the fields and allow you to type. Open Text File will do exactly that. Again it's easy to make a file for this program.