Sri Nityananda Prabhu appeared as the main associate of Lord Caitanya as they propagated the congregational chanting of the holy names of the Lord. He is non-different from Lord Balarama, who appears as the older brother of Lord Sri Krishna, the Supreme Personality of Godhead.
On Nityananda Trayodasi (the appearance of Sri Nityananda Prabhu) His past-times are meditated on and celebrated, and prayers are made to receive His mercy.