I didn't start with a plan to build a portfolio. I started with one problem, built one app, and couldn't stop. Six months later, MRVL Technologies has 17 live apps on the App Store — productivity tools, security apps, invoicing, social, creator tools — and a few more in review. All built solo all bootstrapped, zero VC money. Here's the honest breakdown of what I've learned: What's worked Building getting better with every build. My first app took weeks of deliberation. By app 10, I was going from idea to App Store submission in days. The market tells you more in 48 hours of being live than 3 weeks of planning. A portfolio compounds. Each new app is a chance to cross-promote the others. Users of one app discover two more. The network effect is slow but it's real — and it costs nothing. Attribution matters from day one. I built our own internal SDK (Attribr) to track installs and 30-day retention across every app. I was flying blind before that. Now I know exactly which channels drive subscribers who actually stay. The partner programme changed growth for us. Instead of paid ads, I built a referral system where TikTok creators earn cash per paying subscriber they refer. £0.75–£4.00 per subscriber. 50 spots, self-serve signup. The whole thing runs without me touching it. What's failed Launching without research. Two apps got rejected or flopped because I didn't properly map what competitors were charging for vs. giving free. I was over-giving on the free tier and leaving money on the table. I now do a full competitive research doc before writing a single line of code. Trying to do everything at once. At one point I had 5 apps in simultaneous development. Quality dropped, nothing got proper attention. Now I finish and submit one before starting the next. Underpricing. Every single time I've raised prices, conversion hasn't dropped. The first few apps launched at £1.99/mo because I was scared. The later ones launched at £5.99–£9.99 and convert just fine. Where we're at 17 apps live on the App Store 2 in Apple Review right now Attribution, referral tracking, and partner payouts all automated Monthly infrastructure cost: ~£340 across everything The goal isn't to be the next unicorn. It's to build a portfolio of small, profitable apps that solve real problems — and keep growing it. Happy to answer questions about any part of the stack, the process, or the business model. Ask away. — John, founder of MRVL Technologies (mrvltechnologies.com) https://mrvl-apps-page.vercel.app/