SynthQ got a good update today that adds a nice vocoder. You use it with Inter-App Audio Effect port and that gives so even more possibilities.
– Vocoder module with IAA effect port capability. You can now blend your voice or other IAA or AudioBus audio into your current synth sound.
– Matrix Keyboard layout mode
– AudioBus / IAA effects port
SynthQ is available here
Here is my video about a early version of Synth Q