Lets get a few things clear about BassLine. First, its based on the Roland TB-303, a classic monophonic bass synthesizer from the early 1980s that has been instrumental in electronic music and other genres. Some of the reviews seem to blame BassLine for not sounding like a bass guitar, or otherwise being something that it doesnt intend to be. Next, it should be noted that this is one of the oldest music apps in the App Store (originally Nov. 2008), or at least one of the oldest apps that anyone still cares about. While it feels "behind the times" in some respects, its a credit to the developer that an app created about four years before the AudioBus era now features AudioBus support, and is still relevant for music making. Truth be told, there are now a great deal of synthesizers and other apps that can do either a 303 sound, or sequenced bass sounds of all flavors. But I consider BassLine to be a very good option for arranging simple bass parts, doing some filter/LFO tweaking, and then getting those sequences and loops exported from the app through "Open In", AudioCopy, or AudioBus. People who criticize either the character of the sound or the interface of the sequencer miss the point that these things are very similar to how an actual 303 works. If you dont like that approach to writing bass lines, you have other options. But I found the sequencer easy enough to use, and convenient enough to incorporate into my workflow. The app does what it says, does it with quality, is universal, affordable, and a small file size. Thats good enough for me.