This page lists regular builds of RedReader, from the master branch of the public repo:
RedReader is licensed under the GPL, version 3. The full text of the license is available here.
If you wish to receive Alpha updates automatically, add the following repository to the F-Droid client, refresh, and search for "RedReader Alpha":
|Download Link||RedReader_Alpha_179.apk (4.78 MiB)|
|Date||Sat Mar 2 20:48:34 GMT 2019|