DVR Shows states (in the app description in iTunes) that it support TiVo DVRs. It was never tested against any other DVRs. So, to be honest, I have no idea if any other DVRs work or not.
I wasn't sure when I bought it because around here must people call a DVR a TiVo. No Problem I have it in case I get another TiVo. I used to have a TiVo with DirecTV, but when I switched to HD the receiver was changed and it's probably not made by TiVo like the last one was.
Now you know it will not work with DirecTV's DVR