Special Interest
CityForge
Players design buildings and plan cities that must satisfy structural physics, environmental constraints, and citizen needs. Start with single buildings (understanding loads, materials, foundations), progress to neighborhoods and full cities with infrastructure, zoning, and sustainability challenges. The only STEM-focused architecture and urban planning app on iOS for 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. On-device AI personalizes the mentor's responses to your kid's progress — never connecting to a server, never collecting data.
Mentored by Plumb
#FFA726 CityForge lets you be an architect and city planner! Design buildings that can actually stand up using real structural physics, then plan entire cities with roads, parks, water systems, and more. Every building you design has to satisfy real engineering rules, and every city you plan has to keep its citizens happy.
Characters who teach
Meet the cast
Each character in CityForge is one idea about building a fair city: planning for neighbors, shared public space, walkable streets, transit that reaches everyone, and keeping homes for the people who live there, plus trees, mixed streets, stitching neighborhoods together, flood safety and the pipes underground. Plumb, the mentor, introduces each one.
Block
Zoning + density — the badger with clay-block models who teaches zoning as 'plan for the neighbors first, not the buildings'
Read chapter →
Stoop
Public space + community — the old capybara on a wooden stoop who treats public space as the city's living room, foregrounding existing stoop-cultures (Brooklyn / Latin American plazas / Italian piazzas / West African gathering trees)
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Lane
Walkability + mobility — the rabbit in safety-vest with a chalk-spool who teaches streets-as-spaces ('streets are rooms; cars are guests, not owners')
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Hub
Transit nodes — the pangolin in conductor-vest who teaches that transit is about ACCESS, not about cars-vs-trains ('many ways, equal ways; the bus matters as much as the train')
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Dwell
Housing equity + repair — the old owl in a mended quilted-coat who teaches anti-displacement, repair-not-replace urbanism ('repair before replace; listen before plan; the people who live here ARE the design')
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Canopy
Green infrastructure — trees and parks cool the city and soak up rain; shade placed where it is needed most
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Mix
Mixed-use land use — weave homes, shops, and work close so daily life is a short walk
Read chapter →
Seam
Edges and connection — a highway can rip two neighborhoods apart; design can stitch them back
Read chapter →
Berm
Climate resilience — the beaver who builds soft green earthworks that bend and soak up floods instead of walling them out
Read chapter →
Conduit
Infrastructure — the badger who tends the hidden pipes, wires, and drains beneath every street
Read chapter →
Browse all chapters → · What's distributed-narrative methodology? →
What's inside
Building Designer
Design buildings by choosing materials (wood, brick, steel, glass), placing walls and floors, and adding details. The physics engine tests your building -- if i
City Planner
Lay out a city grid with zones for homes, shops, and parks. Add infrastructure like roads, water pipes, and power lines. Balance your budget and keep citizens h
Commissions
Take on design challenges from virtual clients. They might want a tall tower, a cozy library, or an eco-friendly school. Meet their requirements while staying w
Sustainability Challenges
Design buildings and cities that are good for the environment. Use solar panels, green roofs, and smart water systems to reduce your environmental impact.
Mentored by Plumb — on-device AI, no data leaves the device.
How CityForge 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
CityForge 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
CityForge 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
