Currently, I only analyze fdroid applications. To do so, I use a set of scripts you can find here. The language name is the name of the locale on android, so it is basically <language-code>-r<territory-code>, or simply <language-code>. Some other names also appear to be used, but only by very few applications, because they're probably a mistake (they shouldn't be recognized by android I think).
These graphs represent the state of translation of each language, compared to one another, every day. On the first graph, the Y axis is the percentage of applications translated in the language specified on the X axis, on the total number of apps that have at least one translation. The second graph is the same, but on the total number of app.
Languages are classified with a point system: each language gets one point per completed translation, 0.9 points per almost completed translation, 0.7 points per good progress, 0.3 points per in progress and 0.1 points for started translations.
This graph represents the evolution of a specified language, in number of apps in a specific state. Note that on 2019-07-03 I fixed a bug in transmon that allows it to analyse even more applications. You can select your language on the list below:
It seems that the bug prevented it to analyze popular applications, so there is a sudden increase in the number of translated apps (almost ×2) on 2019.07.02. Then I found there were duplicates in the analysis, so the number of translated apps decreases a little on 2019.07.11.