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.
The "HVAC Psychrometric Plus" app is the #1 selling psychrometric application for the Apple iPhone and iPad
$6.99 · In-app purchases
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.
A product spec, screen plans, and build steps for your coding agent.
First kit free with a verified email
Combine features and design from your favorite apps.
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Generating… usually about a minute.
What should your app do differently? Your note travels with the kit so your coding agent builds around your idea.
A product spec, phased build plan, differentiation notes, and screen references.
Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.
Goal: Send a clear invoice after finishing a job.
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.
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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Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
Rork plan preview for HVAC Psychrometric Plus: map the core Productivity workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
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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
Assumption to check: Limited features compared to desktop versions
Validate with people who use this workflow before building.
Hypothesis 2
Assumption to check: User interface lacks modern design elements
Validate with people who use this workflow before building.
Hypothesis 3
Assumption to check: In-app purchases can be confusing to navigate
Validate with people who use this workflow before building.
Hypothesis 4
Assumption to check: Average app performance and responsiveness
Validate with people who use this workflow before building.
Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.
The "HVAC Psychrometric Plus" app is the #1 selling psychrometric application for the Apple iPhone and iPad. Thousands of happy users have downloaded this useful application for performing quick and simple psychrometric analysis. Just a few reasons why you should buy this application: 1. The Psych Plus is a universal app that it is optimized for the iPhone and iPad. 2. This app was developed by Carmel Software, a company that has been developing software for 25+ years. We are experts in software design and HVAC analysis. 3. It allows you to easily perform single-state and mixed-air HVAC psychrometric calculations. 4. Select and update all input parameters and view the calculated results all in the same screen without switching from one screen to another. 5. Select from 23 different combinations of any 2 input parameters such as "Humidity Ratio / Dewpoint Temperature" and much more. 6. Immediately view updated results as you change the input values using the on-screen slider control. You can specify how much to increase or decrease values as you slide the indicator along the slider mechanism. 7. Send an HTML email and a spreadsheet attachment of all of the single-state and mixed-air inputs and results 8. This app now includes the HVAC Equipment Locator. Click here for details: http://bit.ly/1yTq539 This application contains two separate input modes. The 1st input mode is the "Single-State" mode that allows you to specify 2 psychrometric parameters for a single stream of air and view the remaining 6 calculated values. You can quickly toggle through 23 different combinations of the 2 input parameters and instantly view the calculated results, all on the same screen. The 2nd input mode is the "Mixed-Air" mode that allows you to specify 2 psychrometric parameters for each of two air streams to calculate the mixed air psychrometric conditions. Once again, you can toggle through 23 combinations of the 2 input parameters and view all results in one screen. The following input and output value-types are displayed: 1. Dry-bulb temperature 2. Humidity ratio 3. Relative Humidity 4. Wet-bulb temperature 5. Partial pressure 6. Enthalpy 7. Specific volume 8. Dewpoint temperature 9. Total airflow or mass flow (for mixed-air calcs, only) You can specify additional parameters such as the altitude of the air being analyzed, the atmospheric pressure, different types of units such as degrees F or R, and English or Metric units. The "HVAC Psychrometric Plus" application was designed by Carmel Software Corporation, a leader in HVAC design software since 1995. In fact, Autodesk (the makers of AutoCAD) acquired our analysis software and incorporated it into their leading Autodesk Revit software product. In addition, ASHRAE has hired Carmel Software to develop custom mobile apps to accompany their various standards. We also offer the following apps for the iPhone/iPad: 1. HVAC Residential Load Calcs 2. HVAC Load Plus 3. HVAC Duct Sizer 4. HVAC Pipe Sizer – Gas Low Pressure 5. HVAC Pipe Sizer - Gas High Pressure 6. HVAC Pipe Sizer – Liquid 7. HVAC Pipe Sizer – Steam 8. Steam Tables 9. HVAC Toolkit 10. Psychrometric LT 11. HVAC Pipe Sizer Plus 12. HVAC Pipe Sizer Gas Plus 13. HVAC Quick Load 14. HVAC ResLoad-J 15. HVAC Equipment Locator 16. HVAC Psych HD
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Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.
Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.
Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.
Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.
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.