@robnee The app's author @omz actually supports his apps Pythonista and Editorial very well. From my experience over the last few years, omz releases less frequent, but quality updates. He may not update every few weeks like other apps, but his updates which are a year or two apart are full of huge features and bug fixes.
On top of that, his presence on this forum is surprisingly high. I believe he reads many of these posts, but probably only has time to respond to certain ones. If you want reasurrance of his current support, consider the fact he pays for this forum which is not cheap ( https://nodebb.org/pricing ). The forum is full of experienced people to help. You should also follow omz on Twitter.
omz's apps are the furthest thing away from abandonware as you can get. He just released editorial 1.3 to the App store the other day, hopefully Apple accepts it.