About this app
This app has 42 Trigonometric Proofs of Identities. Work on your own and then compare your answers to the steps shown in the app for proving the identity. Each step in the app is initially hidden and can be shown by clicking on the + button.
Latest release
What’s New
Updated GUI
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Sep 9, 2026 · 12:04 AM $0.99