STEM
InventForge
Which pitching machine is most reliable? Before any formula, invent your own measure of spread from parts, name it after yourself, and test it on new cases. Then meet the textbook's measure and see where the two disagree. Ages 9–14.
▶ Play it nowBuilt for sittings of about 20 minutes on the screen. That is our design budget, not a measurement.
Meet your mentor
Every Spark & Anvil app has a friendly mentor character that demonstrates, asks, and patiently scaffolds learning.
#142e14 Characters who teach
Meet the cast
InventForge has two inventors. Tinkerwell builds a measure from parts before any formula, and Margrave tests it on new cases.
Tinkerwell
builds her own measure from parts before she meets any formula
Margrave
A tester - tries every invented measure on new cases, and keeps the ones that hold
What's inside
Learning goal
Which pitching machine is most reliable? Before any formula, invent your own measure of spread from parts, name it after yourself, and test it on new cases. Then meet the textbook's measure and see where the two disagree. Ages 9–14.
How InventForge handles your kid's data
- ✅ All progress, settings, and AI-generated content stays on the device
- ✅ No analytics, no tracking, no third-party SDKs
- ✅ Free — no ads, no in-app purchases
- ✅ No personal information collected from children — in line with COPPA (updated by the 2026 FTC amendments)
- ✅ No chat with strangers — play-together rooms use a short code and preset emotes, never typed messages