Just a month ago AUM was released and already it has a nice update out with a ton of new features and fixes! The actual changelog is quite long, so I'm only including the new features here. Check iTunes for the complete list.
What's new in AUM v1.1:
- Sync end of recording as well as start, for making beat-perfect loops.
- Display recorded num beats at each channel while recording.
- Allow channels input/output as sources for the main bus meter.
- IAA/AU nodes: MIDI filter with channel mask and note range.
- Multiple AU plugin windows can be shown simultaneously.
- Separate mono hardware inputs/outputs makes it easier to use mono channels.
- Selection of Metronome output channel.
- Allow saving user presets for AU plugins.
- Round-trip latency compensation when recording hardware inputs.
- 'All Notes Off' button for MIDI destinations.
- 4 more IAA/AB output ports, making it 8 in total.
- New 88.2 kHz sample rate option.
- FilePlayer: MIDI controllable Rate parameter.
- FilePlayer: Beat Offset setting.
- Setting for default Bus Send amount.
- Setting for initial PRE/POST for first FX slot in new channels.
- Save/restore bypass-state for nodes in sessions.