To add a blur overlay to your video you first seek to where you want to start the overlay. Then click the "Tools" menu button above the timeline and select "Overlay" and then the "Blur" option or you can press the "O" key and then the "B" key. You can drag the overlay to position it over your video. You can also fine tune the position by holding down the Ctrl key (or Command key on the Mac) and then pressing the arrow keys to nudge the overlay around the video. You can control the opacity of the blur using this slider. By default the blur overlay won't have a transtion so it will just appear. You can add a transition in or out by clicking these buttons. To choose the section of video your overlay appears over you can drag these bars over the timeline to select the start and end point. You can also jump the start point to your current seek point by clicking the "S" key. Or jump the end point to your current seek point by clicking the "E" key. Its also possible to animate the overlay so it changes over time which is useful with the blur if you are trying to blur text that is moving on the screen. We cover animation in another tutorial. You can preview your overlay by pressing the Preview button which will seek right before the overlay start then play through it and stop shortly after the overlay is done. Once you're ready to commit you press the OK button or the Enter key Anytime you make a change to the recording it is automatically saved on your computer. After the overlay is added a colored span will show where the overlay shows on the timeline. If you want to later edit the overlay you can seek back to that spot on the timeline then click this icon which will bring you back to the overlay controls. And you can remove the overlay by clicking this icon. Or you can also use the undo or edit history drop down to go back in time before you added the overlay. The last used tool will be listed next to the Tools button above the timeline so you can easily use the same tool again by clicking on it here.