I started on my first Android app two months after the platform’s 1.0 launch. I felt late to the party. Round one of Google’s Android Development Challenge had already concluded, and the five million dollar prize pool was already rewarded.

I figured it was still worth a shot. A colleague had made a bunch of money off of iPhone apps during the initial gold rush, including a few thousand dollars on a well-crafted tic-tac-toe app. I figured the same would happen on Android, and hell, I already knew Java.

When I got my Android Dev Phone 1 in December, 2008, I noted about 140 apps in the Android Market (the precursor to Google Play). The “Cards and Casino” section was quite light on content, and I had just spent two years working on poker and slot machine software.

There was no clear path to making any money at that point. The Market did not support paid apps yet, and there was no ad library. I figured the matter would be settled soon enough, and so another colleague (graphic designer) and I set to work on a simple slot machine game.

Documentation was reasonable, if a bit sparse. I worked off the original Lunar Lander example code. It had a lifecycle-related bug, which stayed open on the Android bug tracker for 6 years before someone finally marked it obsolete. I had considerable difficulty maintaining 30+ frames per second while still updating the view when I intended to. I remember being desperate enough that I tried calling draw() recursively. It worked great for a second or two! Perhaps the biggest technical achievement was a “pullable” lever that tracked the user’s finger.

Within about a month, we were ready to launch Beat The Joker Slots. We were the twelfth entry in the “Cards and Casino” category. AdMob had just published its initial SDK, and I set it up to refresh an ad every ten spins. The immediate results were striking, though it slowed down pretty quickly, per this email I sent to my collaborator:

“So in the first hour, it made $9. After 2 hours, it was at $15. Then it slowed down a bunch – 12 hours later, it has made $20. I blame this somewhat on admob having a bunch of repetitive ads, and also, they seem to have ran out of unique ads to serve to the user base, the fill rate (how often they provide an add when I ask for one) fell from 99% to 78%. However, we’ve already had 10000 impressions, which shows we really are getting decent volume. Latest count shows 1200 downloads, with a rating of 3.75 stars, which is pretty great for a game that I personally would get bored of in under 3 minutes.”

We settled into a pretty nice place, though. Beat The Joker peaked at #4 in its category. Along with a reskin (Zombie Jackpot Madness), we generated about $300 a month from Admob (and a few other advertising SDKs) for a solid three years. The two apps ended up with over 650,000 downloads combined. It’s pretty remarkable, considering how basic those games are. If I published them today, I doubt I could recoup the $25 I paid to open the developer account.

I didn’t know all that much about advertising then, but I saw a list of most valuable keywords on AdSense, and “mortgage” was one of them. I thus conspired to create Real Estate Droid, a front end for a half dozen real estate APIs I found. It included an auto-updating “show me the nearest home for sale” feature, which I thought was pretty innovative in early 2009. I included a mortgage aggregator’s quotes for a modest fee, and displayed Adsense ads in a WebView to get that valuable real estate advertising. The UI was completely un-styled and generally ugly. I didn’t have access to MLS systems, the most comprehensive database of US real estate for sale. However, it was the second real estate app in the Market, and hit 100,000 downloads in relatively short order.

Network requests were tougher back then. Real Estate Droid launched before Android Cupcake, the release that included AsyncTask. Developers often sneer at AsyncTask nowadays, and perhaps rightfully so. Back then, it was a godsend. Before AsyncTask, I needed to deal with Handlers directly for network requests, and there wasn’t a lot of advice online on how to get it right. (Never mind processing a SOAP API… I think that’s a pain even today.)

Updating a ListView asynchronously was even worse. List items get recycled as they move off screen, and if you’re not careful, you may end up overwriting a list item’s content when a response comes in for a request you issued during that item’s previous lifetime. The official Android Developer Blog addressed this issue a year later, but by then, I had already spent way more than my fair share of time figuring it out on my own.

Adsense served very valuable ads for a few weeks before I got banned. Six months later, I heard from an Adsense representative who personally invited me to integrate their beta Android SDK. Go figure. I learned that they had been upset that I was showing web ads in an Android app, but that was no longer a concern. I was back in business!

It got better. Admob and Adsense would both piloting new ad products from time to time, and they were both willing to make some financial guarantees to secure my participation. From my perspective, it seemed crazy – Admob had been acquired by Google, and it was as if they were competing against each other. From their perspective, I can only imagine that my royalties amounted to rounding error.

That was the high water mark for my app empire. If I had built a multi-game casino app, or a real estate app with a top-notch UX and partnerships with Realtors, I might’ve been able to keep growing. Instead, I focused on my day job, and better apps slowly ate my lunch. After a few years, API dependencies shut down and I unpublished Real Estate Droid.

Regardless, I consider the effort a huge success. My app income translated to an attractive hourly rate. When Android later became popular enough that every business was saying “Oh, and we need an Android app, too!” (2010), I became the lead mobile developer at my day job. In 2012, I joined the Android team at Google and became one of the founding engineers on the Project Fi. I was always a tiny bit starstruck whenever I ended up on an email thread with the engineers whose names I remembered from early Android. I continue to work at Google, though lately I’ve shifted my focus to Machine Learning. TensorFlow feels a lot like Android 1.0 did. Everything feels new, full of potential, and occasionally, a bit of a mess.