It's likely you are referring to Nikola Tesla, the famous inventor and electrical engineer. While Tesla made many groundbreaking contributions to science and technology, he did not develop any anti-gravity devices.

The concept of anti-gravity is still largely theoretical and has not been scientifically proven. There are many misconceptions and conspiracy theories surrounding Tesla and his work, but none of them have been validated by the scientific community.

If you're interested in learning more about Tesla's inventions and contributions to science, I recommend researching his work on alternating current (AC) electricity, radio, and other fields.