Hi Thomas,
The latest news were that it should be ready before the end of the year. I would suggest to follow this post for latest news about Pix4Dcapture (click “Follow” at the top right of the post): https://community.pix4d.com/t/3879
This other post is also discussing the subject of polygonal flights for Android, feel free to Follow it as well: https://community.pix4d.com/t/3715
We will post updates as soon as the feature is released.