You can help fight Covid-19 with your (likely idle) single-board computers! BOINC has a Linux client with a wide range of distributed computing projects available. Rosetta@Home is working to fight Coronavirus, as well as other diseases, and has work units available for ARM64 devices! They never got the viral coverage of Folding@Home, so it is likely there will continue to be plenty to go around. You can also join the Destination_Linux team I created here:
They also have work units for other architectures, but ARM is of particular interest to me because I have an always-on but otherwise usually idle Rock64 running Debian 9. SETI@Home recently got retired, and Folding@Home has no support for ARM devices.