Bell is a countdown timer residing on your menubar, with some special functions, if you would read on.
First of all, you have two countdown durations at the same time.
• this means that you have two durations set, a primary one and an alternate
• you can switch between these two easily
• a good example would be back to the school days, you had, say, 40 minutes for a class, then a 10 minutes break
You decide what to do when the time is up
• the app does the counting down for you, but you tell it what to do when its job done
• for now, some actions are provided
• play a sound
• show one of the interfaces of the app
• show system notification
• run AppleScript
• run shell script
• continue counting down or switch to the alternate duration
• and you pick the actions and arrange their order
It is just there at your service
• global shortcuts are available
• it will appear in your working screen when in multiple displays settings
• it costs little system resource when working in the background
And here are some not-so-obvious keyboard pressings if you prefer
• when in timer interface
• spacebar: resume or pause the countdown
• L: switch to the alternate timer
• G: start the current countdown again
• when in the Preferences interface
• A: show actions
• C: show shortcuts
• when in the app
• CMD+,: show Preferences
• CMD+/: show app info
• Delete: back to last interface if available
• CMD+Q: quit the app
