Arduino Slovakia - CTC timer in ATtiny85 microcontroller
ATtiny13 - simple timer on TM1637 - Łukasz Podkalicki
GitHub - khoih-prog/ATtiny_TimerInterrupt: This library enables you to use Interrupt from Hardware Timers on Arduino AVR ATtiny-based boards (ATtiny3217, etc.) using megaTinyCore. These ATtiny Hardware Timers, using Interrupt, still work even if
ATtiny85 microcontroller tutorials, Part 6: LED intensity control using potentiometer and ATtiny85