Ok, it's a bit of an exaggeration, they definitely still do projects, but there's seems to be a real shift in focus now.
Most of what they do now is stripped down privacy focused versions of existing stuff rather than innovation like they had in the FlyWeb days.
Trying to not get destroyed by Google does wonders to your focus I would imagine
Looks like both Core and Android versions were abandoned back in 2016. Oddly enough, the web version was abandoned in 2018. Still, all versions seem to be React based.
The sole change to the website in 2018 was changing the Twitter URL in the footer away from a dead account. Not really abandoned any later, just someone sent a cleanup to a deprecated site.