Uses for Tivos when you drop cabletv

So I have two Tivos Series 2 and 1 Premiere that are lifetime paid. I'm preparing to drop cable tv because it just discontinued all analog and you have to pay for each digital cable box. Costs just keep rising so I plan to drop it.

Is there any way to recycle these Tivos for recording shows via apps or perhaps use them with a computer for recording?

I don't think I can sell them because the paid lifetime fees don't transfer, right?

MK