Op-amp Circuits projects is an Android application developed by adamapp, available for free download on the Google Play Store. This education and reference app provides a comprehensive guide to understanding the working of operational amplifiers (op-amps) - a fundamental component in analog circuits. The app is designed for beginners who want to learn the basics of op-amps, as well as for advanced users who want to explore more advanced circuit designs.

The app contains detailed information about the op-amp, including its origins and how it is used in analog computers. By using negative feedback, the characteristics of an op-amp circuit, its gain, input and output impedance, bandwidth, etc., are determined by external components and have little dependence on temperature coefficients or manufacturing variations in the op-amp itself. The app also covers different types of differential amplifiers, including the fully differential amplifier, the instrumentation amplifier, the isolation amplifier, and the negative-feedback amplifier. Overall, this app is a great resource for anyone interested in learning about op-amps and their applications in analog circuits.