Simple Clock displays the current time directly on its extension button. Moreover it has a simple alarm function, where multiple alarms can be set.
The idea is to replace the clock element from older Opera versions prior to Opera 15. It is primarily intended for users who have their taskbar hidden or disabled and still want to keep an eye on the time while browsing.
How to use the alarm:
The alarm menu can be accessed by clicking on the extension button. To create a new alarm, enter the desired time in the HH:MM format and hit the enter key or click on the + icon next to the input field.
The alarm gets added to the list of existing alarms with a colored orb on the left side. Green means the alarm is active and will trigger the alarm sound. Red means the alarm is inactive. To toggle an alarm active/inactive click on the colored orb. To stop the alarm sound click on the extension button.