STEM

FunctionForge

Interactive function laboratory — input-output machines, function tables, linear/quadratic/exponential functions, and real-world data fitting. Visual "function machine" component builder bridging arithmetic to algebra.

Meet your mentor

Every Spark & Anvil app has a friendly mentor character that demonstrates, praises, and patiently scaffolds learning. On-device AI personalizes the mentor's responses to your kid's progress — never connecting to a server, never collecting data.

FunctionForge mascot demonstrating — demonstrating

FunctionForge mascot praising — praising

FunctionForge mascot thinking — thinking

FunctionForge mascot encouraging — encouraging

In planning 8 themed avatar accessories Swift 6 · SwiftUI · FoundationModels NGSS CCSS Math ISTE Hero color: #29B6F6

Engagement: Learn · primary

FunctionForge is a fun math lab where you explore how functions work! You will build "function machines" that take a number in and spit a number out, graph lines and curves on a coordinate plane, and discover patterns in real-world data. It is like having your own math laboratory on your iPad.

Distributed-narrative cast

Meet the cast

The four-condition adoption test (from `GUIDE_DISTRIBUTED_NARRATIVE_METHODOLOGY.md` § 2):

Stride the Pattern-Walker

Linear functions (constant rate of change)

Echo the Sameness-Keeper

Constant functions (zero rate of change; output unchanged regardless of input)

Arc the Curve-Catcher

Quadratic functions (parabola — symmetric rate-of-change-changes)

Burst the Doubler

Exponential functions (constant *multiplicative* rate of change)

Pivot the Rule-Switcher

Piecewise functions (different rules for different input ranges)

What's distributed-narrative methodology? →

What's inside

Function Machine Lab

Build your own function machines by connecting gears and parts. Drop a number into the machine and watch it transform! Try different inputs to figure out the ru

Graph Canvas

Plot points on a coordinate plane and watch lines and curves appear. Drag points around to see how the graph changes. You will learn about slope, rate of change

Data Lab

Explore real-world data like temperature, sports scores, or animal populations. Place dots on a scatter plot and drag a line of best fit to find trends. See if

Pattern Discovery

Find hidden patterns in number sequences. Once you spot the pattern, write it as a function rule. This is your bridge from playing with numbers to writing real

Mentored by Domain — on-device AI, no data leaves the device.

How FunctionForge handles your kid's data

✅ All progress, settings, and AI-generated content stays on the device
✅ No analytics, no tracking, no third-party SDKs
✅ No ads, no in-app purchases — you pay once
✅ COPPA compliant under the 2026 FTC amendments
✅ Parental controls + session limits + content filters built in

Full parent privacy guide →

Built with ForgeKit

FunctionForge runs on ForgeKit — the open-source Swift Package Manager framework that powers every Spark & Anvil app. ForgeKit ensures consistent accessibility, COPPA compliance, and design language across the portfolio, so your kid's progress and preferences feel coherent across every app they touch.

Coming to the App Store

FunctionForge is in active development. Email us to hear when it ships — no marketing, no spam, just a one-shot launch announcement.

Email me at launch