Well it has been around a year with yii for me and has done a lot of good for my projects. Recently I decided to rewrite an application on the web to Yii for internal use as I felt it could be done better.
My issue was the SQL schema was 1 big SQL file and I got tired quickly building migrations. I found one other generator that was like mine but it wasn’t exactly what I wanted.
As for instructions, put in your protected/gii folder or whatever other folder you have added to your gii generator path in your app configuration.
Then like others, go to gii, and use. It uses all the model generator code so it can build migrations for an entire database in one go.
At present it only creates fields and handles primary keys.
Feel free to submit pull requests!