I have two Android phones, one is Android 7, one is Android 6. The Android 7 phone joined 10 projects, including Enigma, and runs them all fine. The Android 6 phone had trouble finding any projects at all, and eventually I got 6 attached from the master list within the standard Boinc client (same version on both phones - 7.4.53). The other 4 (Universe, World Community Grid, Enigma, and Einstein) do not appear in the list to join, and if I try to join by URL, nothing happens. No failure notice, nothing, it just doesn't add the project. Any ideas?

This project has been stuck with no work for months.

But BOINC projects in general don't seem to put much effort into maintaining versions of their compute modules for older systems so it may be that the Android 6 is just not going to work.