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
Pool Water Calculator
Pool Water Calculator is an all-in-one pool and spa management suite, providing everything you need to quickly balance and maintain pool and spa water chemistry.
$4.99 · In-app purchases
PRICE
$4.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
★ 4.6
94 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.
Build your own version
Build Kit
Make this idea yours
A product spec, screen plans, and build steps for your coding agent.
First kit free with a verified email
Add to a Remix
Combine features and design from your favorite apps.
Kit ready. Verify your email to download it.
Generating… usually about a minute.
Make it yours Optional
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.
JavaScript is required to complete mailbox verification.
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 Pool Water Calculator: map the core Lifestyle workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
Preview ready. Verify your email to reveal and copy the full prompt.
JavaScript is required to complete mailbox verification. Return to this prompt preview.
Continue in Rork >
Affiliate link: CloneChart may earn a commission at no extra cost
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 input validation and real-time feedback.
Assumption to check: Users find it difficult to enter precise measurements.
Validate with people who use this workflow before building.
Hypothesis 2
Allow users to save custom calculation settings.
Assumption to check: Limited customization options for calculations.
Validate with people who use this workflow before building.
Hypothesis 3
Provide educational content and tips based on results.
Assumption to check: Lack of detailed explanations for chemical requirements.
Validate with people who use this workflow before building.
Hypothesis 4
Test and optimize UI for various screen sizes.
Assumption to check: Inconsistent user experience across different devices.
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
Pool Water Calculator is an all-in-one pool and spa management suite, providing everything you need to quickly balance and maintain pool and spa water chemistry. Quickly Balance and Maintain Your Pool Chemistry Chemistry Calculator – Enter current levels and instantly see precise chemical dosages for nearly any concentration (1% to 100%) using our advanced pool calculator. Pool Volume Calculator – Find the exact volume of your pool, hot tub, or Jacuzzi, ensuring accurate chemical dosing every time. Track and Visualize Your Water Chemistry Data Logging – Easily save and edit water test results, chemical additions, and maintenance events. Flexible Tracking – Record multiple parameters, including pH, free, combined, and total chlorine, bromine, total alkalinity, calcium hardness, CYA, borate, ORP, salt, TDS, nitrate, phosphate, water temperature, CSI, LSI, and turbidity. Reactive Graphs – Spot trends, identify issues early, and keep your water chemistry on target with visual insights. Customized to Your Unique Pool or Spa Tailored Recommendations – Enter your liner type and water profile to get personalized targets for your pool or jacuzzi. Multiple Profiles – Manage up to five different pools or spas, each with unique chemical levels, treatments, and notes. Dosing Guide – Understand each parameter’s role in pool chemistry, plus usage tips for the most common pool chemicals. Broad Chemical Support Balance your pool or spa with a wide range of standard and customizable chemicals, including: - Disinfection & Chlorine Options (Calcium Hypochlorite, Sodium Hypochlorite/Bleach, Dichlor, Trichlor, Lithium Hypochlorite, Bromine Granules) - pH Adjusters (Sodium Carbonate, Hydrochloric/Muriatic Acid, Sulfuric Acid, Sodium Hydroxide, Sodium Bisulfate/Dry Acid, Sodium Thiosulfate) - Alkalinity & Hardness (Sodium Bicarbonate/Baking Soda, Sodium Carbonate/Washing Soda, Calcium Chloride, Calcium Chloride Dihydrate) - Stabilizers & Specialty Chemicals (Cyanuric Acid, Pool Salt, Borax Tetrahydrate, Borax Pentahydrate, Boric Acid, Boron Sodium Oxide Tetrahydrate, PR-10,000) Seamless Backups and Multi-Language Support iCloud Integration – Safely back up and restore profiles, water test history, and settings. Metric & U.S. Units – Switch between units for total flexibility. Language Support – Available in English, Spanish, and French. Stop second-guessing your pool chemistry. Download Pool Water Calculator today for stress-free pool and spa management with accurate dosing, precise water balancing, and insightful tracking—all in one intuitive app.
Written user reviews are not shown here. Check current App Store reviews >
Screenshots
< Scroll to see more >
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-navigation/native
react-native-paper
zustand
expo-constants
expo-linear-gradient
formik
BUILD KIT DIFFICULTY
Intermediate
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.
