That was fast. Since launching on June 25, Second Life's mobile app for iOS and Android has been downloaded well over 20,000 times. That's a safe estimate, because Google Play now lists the Android version of the app as having over 10,000 downloads, and smartphone usage between iOS and Android typically skews 50/50, very roughly speaking. Based on previous reporting, I'd estimate iOS/Android ownership among SLers skews about 60/40, so estimating 20,000+ is on the conservative side.
Notably, that's double the Google Play downloads from only last week.
Also notable: Only Premium/Premium+ users can currently use the app, so quite a lot of them have installed the mobile app:
"How about making the app available on another site not so restrictive?" asks Kaylee West.