First of all, you will need to select the alphabet that the fsa will use. Click on the Alphabet button and choose an alphabet.
Second, you need to create a start state. Click in the white area with the shift button on your keyboard held down. A circle should apear in the area. This is the new state.
Third, you need to left click (control click on Mac's), to get the menu for the state. Make this state the start state, by going to the start state menu item. When it is a start state, a little arrow will appear next to it.
Fourth, create another state by clicking in empty area with shift click again.
Fifth, add a transition by shift clicking on the first state and dragging to the second state. When you are done, you should see an arrow from the first to the second state. If you right click (or control click on the Mac) you will get to select the symbols that the state takes. When you select symbols in the alphabet, they will be drawn above the arrow.
Lastly, make sure that you select at least one final state, by selecting the menu and choosing final state for a state.
Next, type a string into the tape.
Then, run the string through the fsa by pressing run, and then press step until the machine either accepts or rejects.