The book “Gravity 2.0” is now available through iTunes as an epub download. The book is playable both on iPods, iPhones, but is best viewed on the iPad. Please note that all links to the over 300 references in the book are active in this version. There is also a link to the “Gravity Flyways” Google Earth kmz file. However, the current version of Google Earth on the iPad does not allow playback of live 3D models through Google Earth.