Vowel Synth for iOS updated and now it's polyphonic

The somewhat strange Vowel Synth gets a little update:

• Two-vowel polyphony!
• Use 2 fingers to generate 2 vowels at different fundamental frequencies.
• More accurate settings
• Edit gray text boxes on the Settings page by tapping them.
• 2:1 (octave)
• 3:2 (perfect fifth)
• 4:3 (perfect fourth)
• 5:4 (major third)