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
Free VPN – Fast & Secure Proxy
Free VPN lets you connect to VPN servers all around the world — completely free.
Free · In-app purchases
PRICE
Free
In-app purchases
BUSINESS MODEL
Freemium
No overall Grossing estimate available
RATING
★ 4.7
43,901 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 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/
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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 Free VPN – Fast & Secure Proxy: 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
Implement a more stable protocol or auto-reconnect feature.
Assumption to check: Frequent connection drops during use
Validate with people who use this workflow before building.
Hypothesis 2
Expand server locations and improve connection speed.
Assumption to check: Limited server locations compared to competitors
Validate with people who use this workflow before building.
Hypothesis 3
Provide an ad-free premium experience with value-added features.
Assumption to check: In-app ads can be intrusive
Validate with people who use this workflow before building.
Hypothesis 4
Simplify subscription options and provide clear benefits for each tier.
Assumption to check: Complexity in subscription management
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
Free VPN lets you connect to VPN servers all around the world — completely free. With just one tap, enjoy a fast, secure, and anonymous internet experience. - Unlimited location options: Tokyo, Paris, London... connect wherever you want. - High-speed connection: No buffering, no waiting — just smooth browsing. - Keeps your data private and encrypted: Your safety is our priority. - Watch a few ads to unlock everything for free. - Want peace and quiet? Go ad-free with our premium version. - Whether you're at school, at a café, or abroad, - Free VPN keeps you protected — and your freedom in your pocket. And remember, you can always reach us at [email protected] Stay free with love. - Subscriptions Payment will be charged to iTunes Account at confirmation of purchase.Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period.Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal.Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase.Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that publication, where applicable. Privacy: https://freevpnapp.co.uk/privacy/ Terms of Use : https://freevpnapp.co.uk/terms/ Contact : [email protected] Free VPN LTD
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.
