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
Panecal Plus Sci. Calculator
[Description]
$2.99 · In-app purchases
PRICE
$2.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
★ 4.8
357 ratings · Top 5%
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/
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 Panecal Plus Sci. Calculator: map the core Utilities 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 customize themes and button layouts.
Assumption to check: Limited customization options for users.
Validate with people who use this workflow before building.
Hypothesis 2
Implement an option to export history to a file.
Assumption to check: No history export feature.
Validate with people who use this workflow before building.
Hypothesis 3
Introduce graphing features for complex equations.
Assumption to check: Lack of advanced graphing functionalities.
Validate with people who use this workflow before building.
Hypothesis 4
Enhance calculation accuracy through better algorithms.
Assumption to check: Inconsistent calculation results in edge cases.
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
[Description] Panecal is a scientific calculator app that allows you to display and modify formulas. It allows you to enter formulas while checking them, which prevents you from typing incorrectly or making calculation errors. It is also possible to reuse past formulas and use variable memory to change only certain values to calculate them. The display shows the cursor, and you can tap or press the arrow keys to quickly navigate to where you want to edit. It has a powerful, flexible and intuitive user interface with support for swiping to scroll through formulas and long-tap to copy and paste. [Features] - Re-calculation by using past formula - Easy editing by using a cursor operation and swipe the screen - Copy and paste formulas text - Formulas history and answers history table - Binary numbers, octal numbers, decimal numbers, hexadecimal numbers calculation and conversion (Max.32bits) - M+/M- memory functions and variable(A-F) memory - Arithmetic operations, inverse trigonometric functions, logarithmic functions, power functions, power root functions, factorials, absolute values, percent calculations, modulo calculation, polar and cartesian coordinate conversion - Angle units (DEG, RAD, GRAD) - Result format with Normal(standard), Fix (fixed decimal mode), Sci (significant figures), and Eng (index is in multiples of 3) - Decimal point character and grouping separator settings [Disclaimer] Please note in advance that Appsys is not responsible for any damage or lost profits caused by the use of this software, or any claims from third parties.
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
Starter
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.
