I have used it for years, not religiously but often enough. I guess that with time you start tweaking it to your particular needs. When I was studying 25 minute

I have used it for years, not religiously but often enough. I guess that with time you start tweaking it to your particular needs. When I was studying 25 minutes was the perfect length of interval while research and write a paper. At work, doing creative work (development/design/UX/...) I found that 25 mins. was too short and it would actually break my focus, thus I changed it to 60/10 min. Nowadays I use an app called Forest, it provides an element of encouragement of how many trees have I planted and how can I get other trees :-D