One app, several markets: why store and language are separate axes

The same package is a different listing in every store and language pair. Treating it as one thing is the most common localisation mistake.

Two knobs, not one

A Play request carries a store (the country) and a language. The store decides whose ranks you see; the language decides which of your translations Play reads and which suggestions come back. Germany/German, Austria/German and Switzerland/German are three listings with three keyword pools and three rank histories.

Most stores have one language, some have several

For Turkey, Japan or Poland the language is a given. Canada, Switzerland, Belgium, India and the United States have two or more real listing languages, and users search in each. If your app has a Spanish translation, the US/Spanish listing is a market of its own.

Localise the keywords, not just the text

A translated description is not a localised listing. Users in each language type their own search terms, with their own accents and word forms; "über" is not "uber" and an inflected noun is still the same keyword. Harvest suggestions in each language, extract terms with that language's rules, and measure ranks there.

What to do first

Pick the one store and language pair that already brings most installs and get its pool measured. Add a second pair only when the first has a stable trend. A tool that keeps the pairs separate but shows them side by side is what makes this manageable.