Seems like a stout competitor to Zapier, from my brief overview.
Also there's IFTT https://ifttt.com, I've never used it but it seems like it's in the same space.
Flow looks and works almost exactly like IFTTT.
Actually it looks and works more like Pipes did. Many visual data flow languages all sort of look and feel the same, however.
Or node-red which is dirt simple to self host with the docker images.
I think Flow is a kind of 'personal-appliance' version of Azure Logic Apps which is a powerful integration platform. Like taking that tech to personal productivity use.