Where can I find the ranking of SmartThings SmartApp usage? Especially the official SmartApps.
Ranking in what sense?
Like how many people download the SmartApps?
SmartThings Engineering has that information, but I don’t think it’s available publicly. And it’s not really a download process, it’s more cut and paste into your account and then they would have the logs of how many people were running it. Remember that the smartapps don’t run on your phone: they run on the SmartThings servers in the SmartThings cloud except for just a few that can run locally, like the official smartlights feature, and those are provided to every hub.
SmartThings does not release that information. It is considered trade secret (both to SmartThings as well as to the individual authors of the SmartApps - who often don’t know how many installs they have).
They did not implement an “App Store” model, despite the Marketplace existing in the SmartThings App. It was abandoned.