I’ve used this and I think it’s a great especially for long tasks that I tend to put off, because it breaks them into manageable chunks. So it’s really helpful for things that – quite frankly – I’d rather not be doing but have to get done. (Studying, housework, long translations). It takes a while to get used to, but for me the biggest advantage is the mandatory break after 25 min. If it stops you in the middle of something, you have a strong motivation to continue.
Caveat: I tried this to help my 9-year-old with his homework, but it didn’t really work. He still got distracted.