SpectrumAnalyzer: FFT Overlay

[About the App] "SpectrumAnalyzer" is an advanced audio DSP visualizer that analyzes and visualizes live microphone input and audio files with high precision. Powered by Fast Fourier Transform (FFT) frequency analysis and a sleek, intuitive dark-themed user interface, anyone—from audio engineers and musicians to curious everyday users—can effortlessly observe and compare the "shape of sound." [Key Features] ■ Real-Time Visualization - Time Domain (Waveform): Displays sound amplitude fluctuations in real time as a waveform. - Frequency Domain (Spectrum): Analyzes and visualizes the frequency components contained in the sound. - Dual Display (Both): Shows the waveform and spectrum stacked vertically for a comprehensive view of sound behavior. ■ Pro-Grade DSP Parameters - Selectable FFT Size: Choose resolution from 512, 1024, 2048, or 4096 samples. - Window Functions: Supports None (Rectangular), Hann, Hamming, and Blackman windows. - Frequency Weighting: Switch between flat "Z-Weighting," human-hearing-matched "A-Weighting," and noise-evaluation "C-Weighting." ■ Snapshot Saving & Overlay Comparison - Instantly calculate the overall average spectrum from microphone measurements or recordings and save it as a named snapshot. - Overlay saved spectra onto the real-time analysis graph to easily compare frequency responses across different sound sources or before/after adjustments. - Freely customize graph line colors for each snapshot (supports preset colors and a custom color picker). - Preview and play back recorded audio right on the spot. ■ Audio File Import & Analysis - Import and analyze audio files (WAV / MP3 / AAC / M4A, etc.) from your device or iCloud Drive. - Save imported audio files as snapshots to overlay, compare, and audition alongside real-time microphone measurements. [Recommended Use Cases] - Audio Equipment & Speaker Tuning: Measure room acoustics and compare frequency balance before and after adjustments. - Musical Instrument Practice & Tuning: Visually check harmonic structures, verify pitch, and compare with reference tracks. - Vocal Training & Practice: Analyze the frequency characteristics of your own voice. - Environmental Sound & Noise Investigation: Identify which frequency bands ambient noise is coming from. [About Spectrum Analyzer Pro] Core real-time analysis, DSP parameter customization, audio file analysis, and comparison with up to 1 snapshot are all available for free. For users looking for even more advanced analysis, we offer the Pro Plan (Monthly Subscription / Lifetime Unlock). - Unlimited Overlay Comparisons: Remove the free plan limit (up to 1 snapshot) and overlay multiple measurement snapshots and audio files simultaneously without limits. - Ad-Free Experience: Remove all banner and interstitial ads for a clean, distraction-free acoustic analysis environment. * Subscriptions renew automatically unless canceled at least 24 hours before the end of the current billing period, and your Apple ID account will be charged. You can manage or cancel your subscription anytime in iOS "Settings" > "Apple ID" > "Subscriptions." [Links] Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/