Splittier — my own full-stack expense product, from mobile app to admin platform

The challenge

I wanted to ship a complete product on my own: a mobile app for tracking personal and shared expenses with friends, plus all the infrastructure to run it — an admin platform for users, subscriptions, categories and access control; a marketing landing to drive App Store and Play Store installs; and a web version for people who prefer desktop. That meant building all four surfaces against a single backend, not stitching together separate tools.

What I built

I built the entire product:

• iOS + Android app with React Native — personal and shared expenses, group balances, settle-ups, push notifications and real-time sync via WebSockets.
• Web app with React + Vite — feature parity for desktop users.
• Marketing landing with Next.js — conversion-focused funnel into the App Store and Play Store.
• Admin dashboard with Next.js — full operational view: users, subscriptions, app categories, access control, behavior tracking and metrics on signups, actions and retention.
• Backend with NestJS + MongoDB — REST API + WebSockets, push notification service, in-app credit purchases and monthly subscriptions on both iOS and Android, plus an analytics pipeline.
• Infrastructure on Cloudflare for CDN and edge.

Stack

The result

Splittier shipped to production across iOS, Android and web with a working monetization stack — both in-app credit purchases and monthly subscriptions live on the Apple App Store and Google Play. The admin dashboard gives me continuous visibility into new users, in-app actions and retention patterns — the data I need to iterate the product. I keep supporting it with maintenance and feature releases.