I agree with Sjors and Dave_Hunt.
tomlukeywood: It's sad to see that your family insist that you do something
you don't want to, and for a good reason. That's something unethical from
them. Don't fell compelled to help anyone with something they insist on
using, despite you telling them that it does no good and doesn't leads
anywhere. You have your right to refuse, your familiars ought to stop
insisting since you mentioned that you don't want to do that. Note that this
applies in general, not only for installing proprietary software. I hope that
your familiars will reconsider their behavior towards you.
I have heard about Popcorn Time though I haven't used it. Maybe it does what
your familiars want. However, given their rudeness of insisting that you do
something you don't want to, they probably deserve that you refuse to help,
even if you find a free software program that does what they want. It's up to
you of course. If you don't want to be confrontational in refusing to install
proprietary software for them, then after explaining why you don't use it,
you can say that in addition you don't know how to install it, since you
don't use it (Which is true as far as we know, because you're asking in this
forum for how to do it).
If you chose to yield to the pressure and install proprietary software you
must seek help elsewhere. We don't support proprietary software, see the
community guidelines linked from every page in this forum. Some distributions
support proprietary software thinking that they will help their uses. Some
users may feel that they need to use proprietary software (However, “to
need” is subjective and often misused as if it was objective; see
<http://ebb.org/bkuhn/blog/2010/08/09/have-to-use.html>) and the developers
of these distributions may agree and facilitate the installation of that
software. That's a mistake. If users see that the community helps them with
free software but not proprietary software, that adds a practical point in
favor of free software. To support proprietary software or something else
which is also unethical wastes that opportunity to add a practical point for
the ethical option, and helps to perpetuate that unethical action.