I started using this technique a couple weeks ago to make it a habit to study or work for 25 minutes and a small break of 5 minutes for long hours. This is the best system that works for me to be productive and to focus when trying to learn something difficult. The app costs $3 bucks from the app store and is available in IOS and OSX, I highly recommend it!
Today, I feel tired but I’m writing a convolver C++ application from the book “Designing audio effects in C++” by Will Pirkle. It’s not an easy, but I’m in page 277 which I feel very proud of myself.