Yes, signatures are reserved for TDR Subscribers.
There is a check box under preferences to show signatures, but I dont see any on my phone, thats the only interface I use.
Myself as well. I don't even own a computer anymore that I get on, the wife has an elaborate dual screen set up in her home office for work but it was provided to her by UHC and we do not get on it for personal use. Would really like to be able to see Sig's at the bottom of each post.