To add a timer to the interface, just click the "Add" button in the toolbar. Before you click that button, you should choose the kind of timer you need: count up, count down or alarm clock - but if you decide to change the sort of the timer later, you can do so easily.
If you need more than one timer, you can choose to add five or even ten timers at once, by selecting the respective number from the menu.
To remove a timer, just click the little "X" button on the corresponding timer. You can also use the context menu of the list, to remove one or several timers at once. Mark the timer(s) you want to remove and hit "Del" on your keyboard or right-click and select "Remove". To remove all timers in the list, click the red "X" button in the program toolbar.
Timers can be moved to another place in the array using drag & drop, just left-click and hold the mouse button pressed, then move the timer and "drop" it somewhere else (release the mouse button). This works best "from right to left": for example, if you want to make Timer #1 and #5 change places, drag Timer #5 to the place of Timer #1. If you want to move a timer to the last place in the interface, drop it on an empty spot on the right hand side of the last timer in the interface.