If you want to make music on iPhone or iPad, you can choose from an embarrassment of fantastic iOS apps. You’ll also find plenty of music effects and recording apps on the platform.
The problem is using two types of apps together, because iOS isn’t nearly as flexible as macOS when it comes to digging into the system. But with a $10 app called Audiobus 3, you can route audio between apps. That means you can send music from, say, a drum machine to an audio recorder, or from your guitar to a sampler.
Further, you can route audio from many apps at a time, letting you create as complex or simple a setup as you like. If you think of Audiobus as a set of virtual patch cables for your iPhone or iPad, you’re on the right track.