Use Timeqube with productivity techniques such as Pomodoro. Set it for 30 or 60 minutes intervals then focus 100% on the task at hand.
Timeqube form factor and light patterns use human peripheral vision to remind you about passing time and when you should get a break. You don’t need to drop your focus while checking how much time there is left. With Timqube it happens sub-consciously.
Timeqube has 30 minute timer program that is friendly with the Pomodoro technique.