In the games such as Knights of the Old Republic, we see vibroblades/vibroswords but I can't remember seeing them anywhere in the movies. Did they appear in the movies? Were they spotted anywhere besides those games?
They are quite prevailant throughout Legends continuity starting in the Old Republic Era and continuing on from there through the Legacy Era, though they aren't all made with cortosis to make them able to block lightsabers. In Return of the Jedi, Jabba the Hutt's skiff guards were armed with vibro-axes.
You can see an extensive list of appearances of vibro weapons on Wookieepedia here
Their first mention (in publishing order) was in the novel Han Solo at Stars' End(1979).
If it was me who'd checked out, would Doc have gone on a crying jag, Sess? Would you? I'm sorry, but life goes on, and if you lose sight of that, sweetheart, you're asking to be dealt out.
Her mouth opened to reply, but she thought better of it and changed tack. Her voice became as sharp as a vibroblade. Very well. Let's do business.
and their first actual appearance in a book was in Han Solo's Revenge(1979).
The swoop-rider turned to the woman with an odd smile. "I thought Zlarb sent you alone." He then stared at Han. "You have a fatal sense of timing, friend." His hand dipped into the utility pouch on his belt. When it came up again it held something that filled the air with an insistent hum.
Han identified it as some sort of vibroblade, perhaps a butcher's tool or surgeon's instrument that the weapons scanner would register as an industrial implement. It had been home-altered to include a large blade, and its haft was filled with a bulkier power pack.