This utility app helps engineers and hobbyists calculate resistor values for circuits using the Timer IC 555. Simply input frequency, duty ratio, and capacitor values to get the required resistor outputs.
555 Calc by Jibiki Works

10+ similar apps compared and reviewed
Whether you want more options like OCCSensaBLE Classic or a completely different take on the same concept, our curated list of 10+ similar apps has you covered. Updated for 2026 with the latest ratings and comparisons.

This utility app helps engineers and hobbyists calculate resistor values for circuits using the Timer IC 555. Simply input frequency, duty ratio, and capacitor values to get the required resistor outputs.









Easily convert between 12-hour and 24-hour (military) time with this app. It offers instant conversion, an interactive time wheel, a reference chart, and widgets for your home and lock screens. An Apple Watch app is also included for quick checks on the go.