I have this same problem.
Misery loves company, I guess. I am not impressed at all at the amatuerish execution of the Verizon FiOS apps.
So, I am using the correct username and password. I am on a Nexus 7 on AT&T wireless.
make sure your nexus 7 is connected to the in home wireless for the actiontec fios router, and then try it again. that app remote function won't work unless you are connected to the same in house network as the set top box, meaning the router. 3g/4g won't work for the FiOS remote
Here is the help website, it gives a lot of good info for getting it to work
Thank you. The help site confirms my suspision that the app is totally, absolutely, useless to manage a DVR from a device away from the home, which is exactly where one would WANT to use it.
If I am home, connected to my slow(non n), disconnect every hour verizon-provided wireless router I can connect my tablet and do exactly what I can do standing in the same room with my TV remote.
I want to use the stupid app when I am AWAY from my home network. I don't need it at home on my home network.
well keep in mind there are two apps in one, the actual fios remote where you change channels is only in home, but the DVR manager, you should be able to do away from the house. but for that you have to enable it in your DVR.
So when you get home, go to menu>settings>remote dvr and select mobile. register your phone number, and then that will enable the feature for you to use with your cell and that app.