Hello,
I just joined here today, but have read here for many months. For reference, I'm using a Jailbroken iPhone 5S, on IOS 7.0.1
Anyway, here is the way to get the Tivo app to work, where it won't detect the jailbroken phone. This is done using an older version of xCon, 37 beta 7. You will need iFile or something that can install a deb.
Credit goes to leem8181;
Go to Cydia and search for xCon, then scroll down to "Submit an app".
Next, under "open", scroll down to a post called "Tivo" post 317, by Rogreu.
Next, tap on that post and you will see a reply by leem8181. I copied that link that he had for an older version of xCon, 37 Beta 7. I then used iFile to install the deb. Now my Tivo app works, letting me stream live from my Tivo Roamio at home, over the 4G cellular network. No "Modified device' message.
I don't know if this will work for other apps, as I have not tried.
Apparently, this guy leem8181 experimented with different versions, until he found one that works.
Good luck and please post your results, I'm curious.
Here is a link. Hope it's ok to post.
https://github.com/n00neimp0rtant/xCon-Issues/issues/317?source=cc