Video Manager is a powerful tag editor and manager for MKV and MP4 video and audio files.

Features:
Edit Matroska tags in MKV, MKA, MKS and MK3D files
Edit MP4 tags in MP4, M4A, M4B, ALAC and 3GP files
Manage cover arts
Search for and download movie details and poster from The Movie Data Base
Powerful search functionality to find video and audio files in your library
Edit all meta data atoms (MP4)
Batch rename files based on their meta-data
Full unicode support

Whats New:
Updates: official site does not provide any info about changes in this version