Version 4 of the Soundcloud iOS app has been released today, and its update notes carry news of an as-yet-unannounced new service: Soundcloud Go. Free for the first 30 days and $12.99 per month on iOS thereafter, Go appears to be Soundcloud's venture into the world of paid music streaming subscriptions, with the company promising a newly expanded catalog of artists and an entirely ad-free experience. Offline playback is also available, and the Go name in itself suggests a focus on attracting mobile users.

$9.99 on web and Android, $12.99 on iOS

Soundcloud is already one of the most popular free music destinations online, however it's been grappling with the issue of how to turn its popularity into a sustainable business model. The Google Play Store doesn't yet reflect an update that includes Soundcloud Go, so if you want to get an early taste of Soundcloud's upcoming subscription service, grabbing an iOS device will be your best bet for now.

Update 9:25AM, Tuesday March 29: Now that Go has become official, its web and Android pricing has been revealed at $9.99. That puts it in line with the most common subscription services already in operation, though it will be upsetting to iPhone owners who might want to get onboard. The iOS markup is most likely a reflection of the 30 percent cut that Apple takes on app purchases from its store.