MouseClock is described as 'Shows the current time next to the mouse cursor, and date and more in the tray'. There are three alternatives to MouseClock for Windows and Mac. The best alternative is TimeLeft, which is free. Other great apps like MouseClock are TicTocTitle (Free, Open Source) and Dial (Paid).
TimeLeft is a versatile desktop utility - it can be used as a countdown clock, reminder, clock, alarm clock, tray clock, stopwatch, timer, sticker, auction watch, work days/hours countdown clock and time synchronization utility. TimeLeft uses Winamp skins to show digits and text.
Displays the current date and time in the active titlebar. Features: - Doubleclick the tray icon to copy the date and time to the clipboard. - Highly configurable. Individual settings for the display and the copy.
Dial is a beautiful and intuitive Mac timer app. Set timers quickly using the Dial menu bar item or keyboard shortcut. Features: - Global shortcut to set a timer: type “25m” for 25 minutes, “1h” for one hour. - You can also use time picker from the menu bar.