The fact that the game's servers are struggling to keep up with demand should give you some indication of how many people are using the app, but fresh data from Similar Web suggests that Pokémon GO is bigger than anyone could have predicted.
Astonishingly, Pokémon GO is (as of July 8th) installed on 5.16 percent of all Android devices in the US. That might not sound like much, but the day before that, it had overtaken the rather dubious dating app Tinder in concurrent Android installs.
That's only one part of the picture, however - engagement is another area where Pokémon GO is enjoying incredible success. Over 60 percent of those who have downloaded it in the US are using it every single day - that means approximately 3 percent of the entire US Android population are hooked on catching 'mon. In terms of daily active users, Pokémon GO is roughly equal to Twitter, and given a while longer, it could actually surpass the social network in this regard.
Usage time is also impressive for Pokémon GO. As of July 8th, the app was being used for an average of 43 minutes, 23 seconds a day - that's higher than Whatsapp, Instagram, Snapchat and Facebook's Messenger app. User retention figures are also good.
Of course, the game isn't available everywhere in the world just yet, and Niantic has paused the global rollout while it attempts to deal with the various server issues it is currently facing. That has predictably caused a surge in people looking for alternative ways to install the game, and if you're using Android, that means sourcing the apk file. Popular site apkmirror has experienced an explosion of traffic as people search for the file - it had 600,000 visits on July 5th but 4 million visits on July 6th, the day Pokémon GO launched.