# Educational 3D and 4D geometry iPhone app

Built an iOS app that teaches what a tesseract is and lets users manipulate it. People keep buying it in a small niche.

| Tag | Value | Confidence |
|---|---|---|
| Category | Software and apps | 94% |
| Earns from | One-time sales | 95% |
| Startup cost (estimate) | $1k to $10k | 51% (low) |
| Time (estimate) | Hands-off | 90% |
| Where | Online | 97% |
| Coding | Needs coding | 99% |

Source: [Your best passive income? (2014)](https://news.ycombinator.com/item?id=7094567), Hacker News, drewolbrich, 2014-01-21
Page: https://allsidehustleideas.com/ideas/educational-3d-and-4d-geometry-iphone-app-604e06

## About this data

- Sources are public, first-person accounts: interviews, podcasts and community threads.
- Cost, time and the other tags are machine estimates, each with a confidence score.
- Income figures are the owner's own claim. We don't verify them.
- Link the idea page and its source. Call income figures the owner's unverified claim, and cost and time estimates.