What's "right on cue" mean? Is this a commonly used phrase? I'm not sure what "right" means.

Rebecca

"Right on cue" is used to express that something or someone has appeared or arrived at exactly the right moment. In essence, it means "at exactly the right moment." Here, the speaker has used it to express (sarcastically) that Phineas and Ferb's massive creation can be seen at that exact moment. Ex: And here she comes! Right on cue. Ex: We arrived at 5 PM, right on cue.