Howler Timer 4+

I use this most work days, it's perfect for concentrating on specific tasks. It's amazing how many of the timers on offer in the app store don't simply count down and make it easy to set the time yourself - they seem to want to dictate how I should work and also provide a bunch of things I don't need. I'm very happy with this simple, stylish timer and the gradual crow caws leading up to the iconic wolf howl are the only alerts that don't annoy me. I bought the pro version to say thanks to the person who made it.

Does what it says, and nothing more - very basic and easy to use, no complicated interfaces - just type in your hours, mins and secs and press go. I use it for timing writing sprints, so often do several sessions back to back, and the few seconds of howling that gradually rises to signify the end of a session is far more unobtrusive and annoying than, say, a bleeping or buzzing timer ;)

A flexible app that may be most useful if you have multiple things cooking with different timings, because it provides multiple countdown timers and stopwatches running in parallel, and weight/volume/temperature converters.

To create a timer you can either set the hours/minutes/seconds to count down, or a specific day and time in the future (alarm mode). In the free version you can save one timer, to not recreate it over again. Other free apps allow more preset timers, which would be more useful to me than parallel timers or converters, so I took off a star.

The menubar starts showing the last 60s. Clicking on the menubar icon shows all timers/stopwatches running.

Contrary to what a screenshot above implies, in the free version you can't mute all sounds. You can mute the final 10s countdown sound but not the 'time over' sound. It's by default a long wolf howl, which I find annoying, but you can change it to a shorter system sound.