Not sure if anyone remembers, but several years ago there was a database client very similar to Toad, but specifically for Linux. It was great and the closest thing to a Toad-like interface there was. What ever happened to it? I am surprised it isn’t still maintained. In my opinion, it was far better than any of the current ones, such as SQLDeveloper, DBBeaver, etc.
TOra is developed by a community of Open Source developers. The original (pre 1.3.15) development was done by Henrik Johnson of Quest Software, Inc.
It was updated last year and can be found here