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
ShuBook 2M
ShuBook 2M is an OPDS and Calibre friendly book reader and organizer.
$0.99 · In-app purchases
PRICE
$0.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
★ 4.7
10 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's included16 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 ShuBook 2M: 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
Allow users to create custom shelves or tags for better organization.
Assumption to check: Limited customization options for book organization
Validate with people who use this workflow before building.
Hypothesis 2
Integrate social sharing capabilities for users to share their reading progress and favorite books.
Assumption to check: Absence of social sharing features
Validate with people who use this workflow before building.
Hypothesis 3
Offer more flexible subscription options or features for paid users.
Assumption to check: In-app purchase limitations
Validate with people who use this workflow before building.
Hypothesis 4
Implement offline reading capabilities for users who want to access their library anytime.
Assumption to check: Lack of an offline mode
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
ShuBook 2M is an OPDS and Calibre friendly book reader and organizer. ■ READING BOOKS ① Read DRM-free and password-free books of 3 fluid-layout formats and 5 fixed-layout formats ② Read fluid-layout formats (EPUB, TXT, UPDB) in horizontal page-turning mode ③ Read fixed-layout formats (PDF, RTF, DOC, XLS, PPT) in vertical page-scrolling mode ④ Read in both portrait and landscape orientation ⑤ Long press on text to lookup built-in dictionary, read aloud, and copy ⑥ Sync book reading progress via AirDrop and email ⑦ Support all compatible iPhone and iPad models at native screen resolution ⑧ Provide an option to auto-reopen last book read at the page you left off for fluid-layout formats and fixed-layout formats For fluid-layout formats: ① Customize various layout parameters (font family, font size, text alignment, page margin, paragraph indentation, paragraph spacing, line spacing, letter spacing, hyphenation) and apply color themes ② Import unlimited number of user font files (TTF, TTC, OTF) via AirDrop, DropBox, Safari, Mail ③ Provide 16 built-in eye-pleasing color themes and 3 customizable color themes, where you can control background, text, heading and link colors ④ Jump to any page quickly and precisely via page slider with an unobtrusive reading progress line at the bottom of the page ⑤ Offer Night mode and brightness control by vertical swipe to complement iOS system brightness control via Control Center ⑥ Perform fast full text search and automatically save recent searches ⑦ Save an unlimited number of bookmarks per book ⑧ Long press on text to lookup built-in dictionary, read aloud, copy, search (and correct for UPDB) ■ MANAGING BOOKS ① Manage easily thousands of books in Library ② Group books by titles, authors, tags, and clusters with reading progress display ③ Group books by authors hierarchically in Library allowing multiple authors per book ④ Group books by tags hierarchically in Library allowing multiple tags per book ⑤ Group books by clusters hierarchically in Library allowing adding/removing/editing of clusters and re-ordering of clusters and their books ⑥ Search books in Library by title or author, or with help of the index bar ⑦ Edit book info, including title, author, tags and book cover image, for which you can choose from Album and online sources ■ GETTING BOOKS IN AND OUT ① Provide convenient access to millions of free ebooks from multiple sources (HTML websites and OPDS catalogs), including Dropbox and websites you input ② Perform TXT encoding auto-detection and TXT Smart Break after download/import of TXT files ③ Support downloading tags of books from OPDS catalogs ④ Smart batch download from calibre (and other OPDS servers on LAN) with an option to skip downloading books that are already in Library ⑤ Support iTunes File Sharing to import and export books ⑥ Send and receive books by email
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
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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.
