3 years, no updates. Is this project alive? Is it worth buying on sale if there is no activity on the project?

I want to add my own tileset but can't figure out how to do it. What format do I need. How do I import it? I want to just load a png all at once and place it on a layer but I don't kno if that is possible. Even if I have to go one piece at a time would be ok...

1 year the last update, 6 months the last annoucement, 6 months last dev message in discussions, 5 months since last proof of dev life via mail.

Has this been Abandoned?

Does anyone know of another community platform for this app where the developers provide support? This doesn't seem to be the place for that.