PaintVoice（歌声合成＆作曲アプリ）

PaintVoice turns your smartphone into a singing studio. By inputting musical notes and pronunciation-encoded lyrics, you can hear voices sing using UTAU voicebanks. The app features a piano-roll style MIDI sequencer with 4 vocal tracks, 16 instrument tracks, supports chords and short notes, and can import MIDI and export AAC, MP4, or MIDI. It also supports importing UTAU voices such as Kasane Teto and Namine Ritsu. From version 2.0 you can import vocals (UTAU sound sources).

Designed for easy songwriting, music education, and experimentation, PaintVoice is a free starter tool for mobile vocal synthesis. It is simpler than Vocaloid or desktop DAWs, but great for learning, drafting melodies, and trying out lyrics. It includes copy/paste, Undo/Redo, bulk pitch changes, and can save and share creations in MIDI, audio, or video formats. Open-source components are used under the Apache 2.0 license; note that official support is not provided.