FIR Designer is a pleasant tool for designing and analyzing Finite Impulse Response (FIR) filters using the Parks-McClellan algorithm. Key Features: • Frequency and phase response plots • Error approximations and impulse response graphs • Pole-zero plots for zero location tracking • Multiband differentiator design • Share final specifications or coefficients in JSON format with colleagues. • Starts with a ready-to-edit example FIR filter so you can explore controls immediately. FIR Designer is ideal for engineers, students, and educators who need a practical way to create and analyze FIR filters on iPhone and iPad.