A market report for My MobApp Studio, written up as a scientific experiment. Code: Jupyter notebook my_mobapp_studio.ipynb .

1. The question

Our studio has decided to build a new mobile app and launch it first on the Google Play Store. Before design starts, management asked four questions:

How big is the market, in downloads and in dollars?

How is that split across categories (as percentages)?

Per category, how many downloads does a typical app get?

Anything else that helps us pick the right bet.

2. Hypotheses

Before touching the data, we wrote down what we expected to find, so the data could prove us wrong:

H1. Games are the largest category by downloads.

H2. Paid apps are a small share of downloads; the market is mostly free.

H3. The more an app costs, the fewer installs it gets.

H4. The Family category is the most valuable place for a paid app.

3.…