Airline Crew Calendar Sync App — 1,245 Subscribers, 86% Retention, 159 Integrations

The app sells annual subscriptions direct to airline pilots and cabin crew at under US$20 per year. Customers pay individually — there are no airline contracts or enterprise agreements. New users get an extended free trial with no credit card required, then convert to paid. Trial-to-paid conversion is 42%, and subscribers who convert stay a median of 2.2 years. Revenue arrives through three channels: Apple App Store in-app purchases (~92% of orders), Google Play, and PayPal for web signups. Both stores charge 15% under their small-business programmes. The subscriber base is split between roughly 550 auto-renewing subscriptions and around 690 non-renewing annual purchases that users re-buy each year — converting the latter to auto-renewal is a straightforward retention improvement for a new owner. The product is delivered as a web application plus iOS and Android apps.

The entire stack is C#. The web application is ASP.NET on Microsoft SQL Server, running on a dedicated Windows server, with jQuery and Bootstrap on the front end. The mobile apps are .NET MAUI with XAML — a single C# codebase targeting both iOS and Android — using CommunityToolkit.Maui, CommunityToolkit.Mvvm and Syncfusion.Maui.Toolkit, with SQLite for local storage, Firebase Cloud Messaging for push notifications, and Google Maps for route mapping. One consequence worth noting: because both the backend and the mobile apps are C#, a single .NET developer can maintain the whole product. There is no need for separate web, iOS and Android specialists. The core of the system is a library of over 150 airline roster parsers. These authenticate against airline crewing systems (AIMS, ARMS, Sabre, Geneva, Webcis, Jeppesen, iFlight, Merlot and others), retrieve rosters, and convert them into calendar feeds. Retrieval uses headless Chromium with rotating proxies. Rosters are re-checked every three hours and any changes pushed to subscribers. The Android app was fully rewritten in .NET MAUI and released in 2026. The iOS rewrite is in progress from the same shared codebase.

Pricing is the single largest opportunity. The product sells at under US$20/year against a directly comparable competitor at US$29 for fewer features. Apple reports 86% subscription retention and median tenure of 2.2 years, which indicates customers value the product well above what they pay. Average realised revenue is about 25% below list price as a result. Consolidating tiers and moving to competitive pricing is low-risk and can be tested on new signups first. Conversion rates have never been optimised. The App Store listing generates 72,300 impressions a month but converts at 0.8% to download — and that listing has not been updated since January 2023, so it advertises far fewer supported airlines than the product actually handles. Refreshing store listings, screenshots and keywords is a same-week improvement. Trial-to-paid conversion is already 42%; day-35 download-to-paid is 3.92%. Roughly 100 airline integrations are built but unmonetised. The system supports over 150 airlines; only 60 have paying subscribers. Each dormant integration is a market already technically served, requiring marketing rather than development. Organic installs already arrive from India, Pakistan, Indonesia, Thailand, Ethiopia, Morocco, Iraq and the United States with no local marketing at all. There has never been a marketing function. Total advertising spend is under US$700 a year. No SEO, no content, no crew-community outreach, no referral programme. Growth to date has been entirely word of mouth within crew rooms. New trial signups have halved since 2023 with no intervention attempted — this is a demand problem that has never been worked, not a demand problem that resisted work. A retention quick win exists. Around 690 of roughly 1,245 subscribers are on non-renewing annual purchases that must be manually re-bought each year. Migrating them to auto-renewing subscriptions would remove a significant, avoidable source of churn.

I've owned and run this business since 2011 alongside a full-time flying career. I'm not a developer — the technical work has always been outsourced — and my role has been product direction and support. Since taking a new flying position two years ago I no longer have the time the business deserves. It has been maintained rather than grown: development effort went into rebuilding the mobile apps, while pricing, marketing and conversion were left untouched for years. That's why revenue has declined despite retention holding at 86%. The opportunities are clear and documented, but they need an owner who can act on them. I can't, and the business is better sold to someone who will than left to drift. The development team who know the codebase are available to continue, and I'll provide a full handover.