My app competing with others on the App Store, my focus was the user experience, so having crash reports and knowing how long users spend time in the app was required. The reason is that I have a very segmented product, an app dedicated to foreigners traveling by train in Japan: very few results on the App Store, so a higher chance to get the app downloaded. After two months based only on organic growth from the App Store and 100 positive reviews, I’ve started to check the rank of the app overtime.