I released it on Feb 26, 2012, but the download numbers were very low for about 2 months. Then, I released version 1.1 at the end of April. Sales picked up, and have stayed pretty high since then. So, the bulk of the 1M downloads have come in the last two months.
If you sign up for a free AppAnnie.com account, you can take a look at the rankings history in the various countries.
The app did really well in China/Taiwan/Hong Kong, because I added the Chinese word for "piano" as a keyword. App Store SEO really helps!
Thanks for that last piece of information - I'm looking for concrete examples of where translation boosted sales and this fits the bill quite well. Have you localized for any other markets?
I have not localized the app itself. I feel like that is a lot of work for one person to maintain.
However, I have localized the App Store title, description, and keywords to as many markets as possible. I use Google Translate and my best judgement. Mostly, I just translate the word "piano" into different languages, to improve search. See my German page: http://itunes.apple.com/de/app/tiny-piano/id477014214
This has had a positive impact on sales in Germany, Japan, and Korea.
If you sign up for a free AppAnnie.com account, you can take a look at the rankings history in the various countries.
The app did really well in China/Taiwan/Hong Kong, because I added the Chinese word for "piano" as a keyword. App Store SEO really helps!