This is DEMO version of "Circuit Calculator": an interactive electronics design tool for engineers. Convenience, visibility and ability to find an optimal solution in minimum time. You can buy full version of the application which has much more features in the Google Play store. https://play.google.com/store/apps/details?id=com.vdv.circuitcalculator You can use Filter Designer to design multistage active filters, available in the Google Play Store. https://play.google.com/store/apps/details?id=com.vdv.filterdesigner Full working circuits are only: * Inverting Amplifier; * Non-Inverting Amplifier; * Fully Differential Amplifier; * Low Pass One Pole Filters; * High Pass One Pole Filters; * ZETA DC/DC Converter; Other circuits: * Only default input parameters; * Tuning of circuit component values is not allowed; * Circuit can not be saved; * An internal list of DC/DC converters only; Features: * Amplifiers * Attenuators * Variable Gain Amplifiers * Drivers * Mathematical Operations * Current Sources and Receivers * Lowpass Filters * Highpass Filters * Bandpass Filters * Bandstop Filters * Impedance Matching * Power * Control Loop Compensation * Reverse: calculation of circuit parameters at known values of its components * Logic Solver, from 2 to 6 inputs * Auxiliary tools * Application Notes