Calculatronics: EE calculators is an electronic toolbox app for electrical engineering students and electronics hobbyists. It is a powerful electronics toolbox app, it works well on phones and tablets. You can perform circuit calculations with the app like the one described below.

It includes an EE circuit simulator, a multivibrator, a monostable pulse duration (MPD) meter, a resistor color code, a series resistor, a parallel resistor, a voltage divider, an LED resistor, a Zener diode voltage regulator, an LCR resonance, an LCR Impedance, a Capacitive reactance, an Inductive reactance, a BJT parameters, a Delta -> star, a Star -> Delta, a Current divider, a Parallel RLC, a Series RLC, a Transformer turns calculations, and many more.