There are various meetups around the world that work on altruistic software development. Random Hacks of Kindness is at the top of my mind at the moment.
The main site appears to be down at the moment, but the Australian and Canadian sites are still up, and the Australian one is asking for projects which help with the COVID-19 response.
That got me wondering. What software projects would be high leverage and not currently saturated? Which of them are amenable to being worked on by groups of developers with mixed skills and backgrounds?
This can probably be broken down further into software for different groups. Healthcare workers probably have different needs in this time than people who are struggling to make the case for working from home. My gut feeling is that efforts that helps with social support and mental health support will also have high value over time.