For a .deb package the latest you can get is version 1.1.42
To get the latest, ie 1.2 stable or 1.3.3 dev, you will have to download the source tarball and build it on your system. Links for the source tarballs are at the bottom of the page proxima_centauri provided.
Compaq Presario CQ62 Dual-Boot: Mint 17 Cinnamon, LMDEREADING: Little Brother
by Cory Doctorow