Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Fitbod - Personalized Strength-Training powered by Machine Learning
wnr - Better than pomodoro, this timer app balances work and rest.
JEFIT - Jefit is the #1 popular gym workout app for Android and iOS. Jefit allows you to manage your training routine and keep track of your workout progress easily.
Free Countdown Timer - Free Countdown Timer is a free, full-featured and user-friendly countdown timer for Windows
Hevy - Simple workout logging, insightful analytics, and a growing community of gym athletes.