On the synth side, perhaps the most fully featured app is Noise.io (V. 1.2.2, Amidio Inc.; $9.99), which is both a synthesizer and a sequencer. It has a cool “kaos”-style controller in addition to a virtual keyboard (which is small and limited). It allows you to record and overdub parts (it has three types of sequencers), and has a snap-to-grid feature. Noise.io sounds quite good, and its synthesis and editing capabilities are surprisingly deep. It has three tone generators, three LFOs, six effects, and WAV export. Its biggest drawback is a cryptic and complex user interface. That said, if you're willing to spend the time to learn it, you'll be impressed.
FEATURES, AT A GLANCE
Nine presets from three categories (factory, user and Internet)
Three modes: Free Noise, Sound Key and Control Zone
Control surface elements include volume slider, bpm indicator, bpm marker, mode indicator, accelerometer indicators, current note/pattern indicator, and current preset and bank names