oracle database tools free
SQL Plus is all you need to manage an Oracle Database.
The more you use tools the less you understand what the tools are doing. Unlike other databases there are so many options on how to customize an endless number of parameters. It is not practical to even try and have a tool understand all the options and parameters you need.
Even worse the tools dumb down many of the things one should be thinking about with care.
Learn the data dictionaries and SQL. That is all you really need.
Now after you have paid your dues, every once in a while it is fine to use some cartoon to code tool. The sign that it is time to put it down is as soon as you forget how to do it from a command line.
Part of my bias comes from the fact that I am really good at forgetting things so I almost exclusively use command line tools to remind myself of the things I forgot from the previous week. I don't have enough time to remember command line tools and cartoon to code tools.