NailIT – AI Interview Practice Web Application (React + Node.js)

Important: please read before purchasing. NailIT is NOT a native iOS or Android application and it is NOT built with Swift or SwiftUI. It is a full-stack WEB APPLICATION written in JavaScript and TypeScript: a React 18 + Vite frontend, a Node.js / Express backend, a Supabase (PostgreSQL) database, and OpenAI AI services. An optional Expo / React Native WebView shell project is included for wrapping the web app as a mobile app, but the product itself is a web template. You need Node.js, npm and terminal experience to set it up – no Xcode project is required to run the core product.

Demo Instructions

Demo login: email: demo@nailit.app – password: Demo1234!
This is a source-code template that you run on your own machine or server, so there is no hosted demo site. After completing the one-time setup below, register the demo account above once on the Sign Up screen (or use it to log in), and the full app is instantly testable with those credentials.
One-time configuration required before it runs: a free Supabase project (database + authentication) and an OpenAI API key (paid service for transcription, scoring, speech and realtime voice). Where to obtain every key and exactly which file to paste it into is documented step by step in documentation.html, section 4.2 and 4.3 (“Environment Variables – where to obtain each API key”).
Setup takes roughly 15-30 minutes. Tip: in Supabase (Authentication – Providers – Email) you can disable “Confirm email” so the demo account can log in immediately.
Optional integrations that work out of the box once keys are added: ElevenLabs voice, Stripe / RevenueCat token payments, Branch deep links for the affiliate program.

Everything the App Does

AI scoring of interview answers with GPT-4o-mini: score 0-100, band (Poor to Outstanding), summary, strengths, improvements and follow-up questions
Live Interview mode: multi-round simulated interview with text-to-speech questions, voice recording, Whisper transcription and per-answer scoring
Realtime AI Interview mode: natural spoken conversation with the OpenAI Realtime API, configurable duration (1-5 minutes) and live AI rating option
Drill mode: practice individual questions from a question bank, answer by voice or text, and compare with an AI-generated model answer
Persona system: Medical, Oxbridge and Apprenticeship interview styles with persona-specific scoring rubrics, plus a custom persona
Custom question bank: manage your own primary and follow-up questions per persona
CV upload: paste a CV (stored locally in the browser only) to personalise feedback
My Answers: history of saved attempts with filters (recent / this week / this month), average score, total attempts and delete
Progress dashboard with weekly activity chart and performance statistics
Token economy: per-minute token metering for practice and realtime modes, token balance in the header, token gating with an out-of-tokens modal
Token pack store page (Starter / Plus / Pro) ready for Stripe (web) and RevenueCat / in-app purchases (mobile)
Affiliate / referral program: referral links, 90-day first-touch attribution, clicks / sign-ups / pending / paid earnings stats, plus an admin view
Tutoring marketplace page with tutor search, subject and price filters, and booking call-to-action
Resources section with interview preparation guides (STAR method and more)
Secure email + password authentication: registration, login, logout, password reset, server-side HttpOnly sessions
Account area: preferences (voice, time limit, strictness), data export and full account deletion (GDPR / CCPA friendly)
Row Level Security in Supabase so users can only read their own data
Text-to-speech with file caching, optional ElevenLabs voice, tiered rate limiting and Helmet security middleware
Responsive dark-themed UI with an orange accent, built with Tailwind CSS
Optional Expo / React Native WebView shell with in-app purchases (react-native-iap), Branch deep linking and microphone permissions, ready for the App Store and Google Play

Technology

Frontend: React 18, TypeScript, Vite, React Router 6, Tailwind CSS, Lucide icons
Backend: Node.js 20, Express 4, Zod validation, Helmet, express-rate-limit
Database and auth: Supabase (PostgreSQL) with Row Level Security; SQL schema files included
AI: OpenAI GPT-4o-mini (scoring), Whisper (transcription), TTS-1 (speech), GPT-4o-mini Realtime (voice)
Payments: Stripe webhooks and RevenueCat webhooks + in-app purchase verification
Mobile shell (optional): Expo 53, React Native 0.79, WebView, react-native-iap, Branch
Deployment: any Node host – Render configuration file (render.yaml) included

What the Buyer Gets

Full source code: React web frontend, Express backend server, optional Expo mobile shell
SQL setup scripts for all database tables (attempts, token wallets and ledger, affiliates) with Row Level Security policies
documentation.html: step-by-step setup, configuration, customization and deployment guide with screenshots
Screenshots folder with all preview screens
Environment variable template (.env.example)

Development Disclosure

Portions of this template’s source code were developed with AI-assisted tools. All code has been reviewed, tested and prepared for release by the author.

A Note Before You Buy

This item is a source-code template, not an end-user app and not a hosted service. You will need comfort with the terminal, Node.js and npm, plus your own Supabase and OpenAI accounts. Running the AI features consumes OpenAI API credits. If you are looking for a native Swift / SwiftUI or Kotlin application, this template is not that – please check the technology list above before purchasing.

NailIT | AI Interview Prep Web App With AI Scoring - React and Node