I have added custom MP4 tags to my MP4s but no program I've tried allows me to view them. I've tried Poweramp, Audio Tagger, Build in player, MortPlayer, etc.
They all only show the standard tags (artist, title, etc.) .
For example, I have a tag called Tempo that I want to see. I have no issues with tags on the PC using foobar2000.
Are there any apps out there than can read them?