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
Trailforks: Offline Bike Maps
Trailforks is a trail database & map with over 650,000 trails
Free · In-app purchases
PRICE
Free
In-app purchases
BUSINESS MODEL
Freemium
No overall Grossing estimate available
RATING
★ 4.7
16,324 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 Trailforks: Offline Bike Maps: map the core Navigation 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
Offer more comprehensive offline maps and features.
Assumption to check: Limited offline functionality compared to competitors
Validate with people who use this workflow before building.
Hypothesis 2
Implement robust search and filtering options.
Assumption to check: Difficulties in finding specific trails or information
Validate with people who use this workflow before building.
Hypothesis 3
Simplify UI for better navigation and usability.
Assumption to check: User interface can be overwhelming
Validate with people who use this workflow before building.
Hypothesis 4
Improve the user experience around monetization and feature access.
Assumption to check: In-app purchase prompts can be intrusive
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
Trailforks is a trail database & map with over 650,000 trails. Users can contribute data and then local trail associations have the control to approve & curate the data. Get 14 days of free app use, then upgrade to Trailforks Pro to unlock the map world-wide. Otherwise continue to use the map in your local area for free. App Features: - The largest database of mountain bike trails in the world, including thousands of biking related POI's - Offline trail maps and info. Region updates are incremental and fast - See your GPS location on the map, for trail navigation - Record your GPS location during ride creating a track - Display trail & route elevation profiles and 'scrub' along them to see the location on the map - View local routes that users have created - View trail logs from users and discover how to explore a new trail - Automatic trail routing from your location (or nearest parking lot), to the trailhead of your choosing - Sync and view your saved plans from the Trailforks website - Follow race course routes including colored stages and checkpoints - Lookup region & trail info including routes, photos, videos & more - Use your phone’s compass to orientate the map in the direction you’re facing - View trail status & reports! Always be informed of up-to-date trail conditions & closures - Submit trail reports & conditions from the app, including taking photos of trail issues - Support the areas you ride, by donating 'Trail Karma' - View nearby bike shops on the map, quick links for directions or phoning the shop - View trails on map color coded by popularity - Mountain biking heatmap! - View custom worldwide topo maps designed for outdoor trail activities The Trailforks app is your mobile companion to the Trailforks website. It allows you to download offline trail maps for use on your rides! Terms of Use: https://www.trailforks.com/about/tou/?source=tfapp&app=1 and https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Note: Continued use of GPS running in the background can dramatically decrease battery life.
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 Native
Expo
react-navigation
axios
expo-location
react-native-maps
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.
