it's impressive that 3 person years from _no Java experience_ was all it took. Java and Android are complex ecosystems.

Not to say they couldn't have shipped it in less time. Of course they could have. But it sounds like they shipped something very well built.

But what other languages did the have experience with? If it was something similar like c#/c++/ruby/python then the time to learn java should not be significant.

When it comes to Android, Java by itself is the least of problems. It's the SDK and framework that are tricky, ridden with technical debt and often far from developer-friendly.

I was about to say this. In fact, you have to unlearn a lot of what works and is accepted in server side java when you move to Android. Learning the SDK and Android gotchas was by far the hardest part of my first Android app.

Yes Android is particularly complicated, but not to the point where 3 experienced developers building an app in 8 months is in any way remarkable.

I have never used this app myself, I don't know whether it's complex. I only peeked at the source code. And yes I was referring to the contrast between how neatly written it is, and their lack of experience with the platform, not how fast they did it.

Development on Android tends to be slow overall, owing to numerous intricacies of the platform, but I believe that in general taking some extra time to roll out a clean and polished version 1.0 will pay off when it comes to 2.0 and 3.0. It's always easy to move fast in the beginning, use lots of duct tape and snap something out rapidly, but it comes at a cost and then you get bogged down further down the line