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
Kortext
Kortext provides access to online eBooks from multiple publishers, with enhanced in-built audio and video content, combined with tools to assist learners and academics to make the most of their content.
Free · In-app purchases
PRICE
Free
In-app purchases
BUSINESS MODEL
Freemium
No overall Grossing estimate available
RATING
★ 3.9
1,279 ratings · Top 50%
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 included19 files
A product spec, phased build plan, differentiation notes, and screen references.
- START_HERE
- AGENTS
- EVIDENCE
- SPEC
- BUILD_PLAN
- DIFFERENTIATION
- skills/
- screens/
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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 Kortext: map the core Books 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
Expand partnerships with publishers or allow user-uploaded content.
Assumption to check: Limited book availability compared to other platforms
Validate with people who use this workflow before building.
Hypothesis 2
Implement a cleaner, more focused design layout.
Assumption to check: User interface can be cluttered
Validate with people who use this workflow before building.
Hypothesis 3
Optimize app performance for lower-end devices.
Assumption to check: Inconsistent performance on older devices
Validate with people who use this workflow before building.
Hypothesis 4
Add more annotation tools like audio notes or collaborative features.
Assumption to check: Limited annotation features
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
Kortext provides access to online eBooks from multiple publishers, with enhanced in-built audio and video content, combined with tools to assist learners and academics to make the most of their content. Features include: - Add and read PDF/EPUB files from your iPhone and iPad - Enjoy free access to a collection of over 13,000 eTextbooks - Easy navigation to content, providing quick access to pages - Highlight text in a range of colours and create notes, enabling quick reference of key sections - Add a reference (Harvard or APA), making creation of bibliographies much easier - Read Aloud sections, providing help with accessing content - Increase text size, change font and background of pages making it easier to view content - Search for keywords and phrases within the books directly from your bookshelf, allowing quicker access to relevant content - 500MB of free cloud file storage. Simply upload your study materials and harness the full potential within
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.
SUGGESTED BUILD STACK
React Native
Expo
Supabase
React Navigation
Zustand
React Native Paper
BUILD KIT DIFFICULTY
Expert
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.
