Feature spec
Goal: Send a clear invoice after finishing a job.
- Add a client, line items, a due date, and payment instructions.
- Preview the total before exporting a PDF.
- Keep an editable draft if export fails.
App Overview
Slice Fractions
This award-winning, problem-solving game is an incredibly fun way to learn fractions
$3.99 · In-app purchases
PRICE
$3.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
★ 4.7
470 ratings · Top 15%
Evidence scope: No current overall US chart position is available. Category-chart positions shown in discovery are a separate scope. Revenue is a directional model estimate, not verified earnings.
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Build Kit
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A product spec, screen plans, and build steps for your coding agent.
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What should your app do differently? Your note travels with the kit so your coding agent builds around your idea.
What's included17 files
A product spec, phased build plan, differentiation notes, and screen references.
- START_HERE
- AGENTS
- EVIDENCE
- SPEC
- BUILD_PLAN
- DIFFERENTIATION
- skills/
- screens/
Preview a sample Build Kit No email needed
Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.
Screen plan
Invoice editor: Client at the top, editable line items in the middle, total and preview action at the bottom.
States: Empty draft, validation errors beside each field, exporting, and a retry action that preserves the draft.
Differentiate and validate
Hypothesis: Contractors need faster repeat invoices more than more templates.
First experiment: Test duplicating a previous job with five contractors. Watch where they hesitate before expanding the feature set.
The full kit adds a phased build plan, evidence notes, tool prompts, and implementation guidance. It is a plan for your coding agent, not a finished app.
Usage: Mechanics are fair game; never reuse the original name, branding, assets, or verbatim copy.
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Free quick prompt For a smaller starting point
Quick prompt
Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
// RORK SYSTEM PROMPT
Rork plan preview for Slice Fractions: map the core Education workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
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Opportunities
AI-GENERATED OPPORTUNITY HYPOTHESES
These are generated suggestions, not verified review quotations. Check current App Store reviews and speak with users before treating a possible gap as a requirement.
Hypothesis 1
Implement more diverse and engaging levels with varying themes.
Assumption to check: Limited level variety may lead to user boredom
Validate with people who use this workflow before building.
Hypothesis 2
Simplify the purchase process and provide clearer explanations for users.
Assumption to check: In-app purchase system can be confusing
Validate with people who use this workflow before building.
Hypothesis 3
Offer an option to disable animations for a more focused experience.
Assumption to check: Some users may find the animations distracting
Validate with people who use this workflow before building.
Hypothesis 4
Enhance the progress dashboard with more metrics and visualizations.
Assumption to check: Progress tracking lacks detailed insights
Validate with people who use this workflow before building.
App evidence
Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.
App Store description
This award-winning, problem-solving game is an incredibly fun way to learn fractions. Thanks to the game’s research-proven effectiveness, kids get a head start at school while having fun with fundamental math concepts. Wow! *** Best of 2014 -- App Store, Apple *** *** Editors’ Choice -- App Store, Apple *** *** Editor’s Choice for Excellence in Design -- Children’s Technology Review *** *** Winner of a Parents’ Choice Gold Award 2014 *** *** Gold Medal Winner 2014 -- International Serious Play Awards *** *** Best Family Friendly Game 2014 -- Indie Prize Showcase Awards *** “Teaching without making it feel like a lesson.” -- maclife.com “Slice Fractions is wholly playful learning. At its best.” -- Parents' Choice “There's a lot more to this app than fractions.” -- Children’s Technology Review UNIVERSAL APP: Available for iPad, iPhone, and the new APPLE TV! GOAL: Kids between 5 and 12 slice through ice and lava to clear the mammoth’s path, unraveling the mystery of fractions! FEATURES: • Learning fraction concepts without words • Experiencing an activity reviewed by researchers at a Canadian university (UQAM) • Solving over 140 innovative physics puzzles • Collecting funky hats • Playing in a safe, digital environment. No ads or in-app purchases. FRACTION CONCEPTS: • Part-whole partitioning • Numerator / Denominator notation • Equivalent fractions • Fraction ordering • Subtracting fractions from 1 • Addition TEACHERS: Slice Fractions is based on the following Common Core concepts: (2.G.A.2) (2.G.A.3) (3.NF.A.1) (3.NF.A.3) (4.NF.A.1) (4.NF.A.2) (4.NF.B.3) (4.NF.B.3.B) (4.NF.B.3.C) LANGUAGES: Danish, English, French, German, Italian, Japanese, Korean, Norwegian, Portuguese, Russian, Spanish, Swedish, Turkish, Simplified Chinese and Traditional Chinese ULULAB: We produce fun and pedagogically sound video games. We strive to ensure that these games are intuitive and will lead to profound conceptual learning. We believe we can push the limits of game-based learning. FOLLOW US: • Website: www.ululab.com • Twitter: www.twitter.com/Ululab • Facebook: www.facebook.com/Ululab • Newsletter: www.ululab.com/newsletter Your feedback is much appreciated, so please feel free to provide suggestions for future updates. If something isn't working as you would expect, please contact us: www.ululab.com/contact
Written user reviews are not shown here. Check current App Store reviews >
Screenshots
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Build scope
Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.
Define the first version
Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.
Set boundaries
Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.
Check the hard parts
Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.
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BUILD KIT DIFFICULTY
Advanced
From the Build Kit assessment.
A reliable timeline needs an agreed scope and a technical check. Ask your agent to estimate the phases in BUILD_PLAN.md after that review.
