There is not "a number" of up-to-date maintained plugins for dealing with foreign keys.

The foreign_key_migrations does not have any update since 2009 and is also about to be removed:

Extracted from http://www.harukizaemon.com/2009/09/plugins-grab-em-while-theyre-stale.html,
referenced in the plugin reference of the old guide version:

"And so it is that I will very shortly (within the next month) delete most of the plugins from
my GitHub account (harukizaemon)"

Replace the reference to the annotate_models plugin (unchanged since 2008) with more current annotate_models gem

Rewrote entire section including example code, error message, and work
around.