Fourier App vs Quantum Route Finder

Fourier App is an interactive tool for visualizing and computing Fourier Series of piecewise functions. Define custom functions with multiple pieces and discontinuities, choose the time window, and instantly see the original signal x(t) alongside its series approximation s(t). Browse a built-in catalog with classic examples like sine, cosine, step function, rectangular, triangular, ramp, parabola, and more. View the frequency spectrum with an, bn, and cn coefficients, filter partial series terms, and explore how each harmonic contributes to the final waveform. Includes a theory section covering Fourier Series history, equations, and real-world applications such as audio streaming and noise cancellation.

Quantum Route Finder lets you run real quantum circuits on IBM's quantum computers directly from your iPhone — no simulator, no shortcuts. Your device builds the circuit, submits it to a 156-qubit IBM Quantum processor (Heron r2 generation), and visualizes the measurement results in real time. How it works The app uses a hybrid architecture: your iPhone acts as the controller, constructing OpenQASM circuits and sending them to IBM Quantum Cloud via the REST API. Quantum computation happens on the actual QPU hardware at IBM Research facilities. Everything else — UI, circuit building, result visualization — runs entirely on your device. IBM Quantum account required This app requires a free IBM Quantum account at quantum.cloud.ibm.com. The free Open Plan includes 10 minutes of QPU time per month. This limit is enforced by IBM, not this app. Once your monthly quota is used, jobs will be queued or rejected until the next month. No IBM affiliation — you must create and manage your own account. What you need IBM Cloud API key (free, from quantum.cloud.ibm.com) Instance CRN (from your IBM Quantum dashboard) Available backends ibm_kingston, ibm_fez, ibm_marrakesh (156-qubit Heron r2 processor