Feature Enhancement request

```
Any chance you can add a user-selectable plus-and-minus buttons that when 
clicked move forward/backward the number of seconds the user has defined?

(Alternatively a static plus/minus five or ten seconds button, but user 
selection would be a plus).

Thanks as always.
```

Original issue reported on code.google.com by `kzinn...@gmail.com` on 20 Jul 2013 at 1:27
