Tldr: Works as advertised, good user interface, worth the price on a sale. But doesn't restore timer-progress between launches and the timers won't surpass 100hrs.
Pros: Timing = Everything does what it's supposed to do. It allows you to have on multiple timers for up to one hundred hours.
I've been using it to time how long I take on pages when reading.
It's not an essential tool for everyone, but definitely worth the 1,99€ cost during a sale -50% off if you'll be using it.
Cons: My only unfulfilled expectation is that it won't allow for timers to remain active when turning off the program, like when turning off the computer. I had hoped that it would keep track of the time that had run on its timers when I launching the program again, but in reality all timers are reset upon both closing them on the deskop and upon closing the overall program on Steam. So you can't have a countdown timer for "Time left of the week" or anything like that, unless you don't mind not turning off the program for days. But it's limited to one hundred hours, so that particular example wouldn't exactly work anyway as there are 168 hours in a week.. And if you accidentally closed the program once the timer would reset.. So there's that.
Verdict: it's a great, really easy to use, and rather practical application for me and others who have some reason for running timers. A score of 5/6 is my situational rating of it at the timed time of writing this review.