It's a royal pain to get at - you have to join the project (but the project doesn't show up in the list of projects any more). Once you've joined the project, the download shows up in the usual place. From a thread I started on this, the link is:
https://tech.lds.org/projects?controlle ... ojectid=24
After you join, you have to log out of LDS.org and back in, then the download link works. I think they forgot that side loading is a legit reason to make at least the current release apk freely (and easily) available to all (e.g. my emulator doesn't have the play store, and it's an even bigger pain to get the play store installed on the emulator).
Liz