Thanks to C.Y. Reid (blog) for inspiring me with his game Hug Marine. I'd been wanting to create an android app for some time but his game really compelled me to get started.

Thanks also to Nicola Austin for putting up with me whilst I worked on this.

The music is Vision of Persistence by Kevin MacLeod.

Vision of Persistence by Kevin MacLeod is licensed under a CC Attribution 3.0.
http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100024.
Permissions beyond the scope of this license are available at http://incompetech.com/music/royalty-free/licenses/.

All sound effects are from freesound.org. All have a Creative Commons 0 licence.