I wasn't sure if it was included with Classic or Classic Plus fare, and best I can tell it is not. But on that topic, there is a new (or newish?) interactive grid on the website which makes it much easier to see what the different fare tiers include and what the different fare tiers include for someone with different frequent flyer status levels. That has sometimes seemed a little confusing because there were separate charts. Now you can click on your status level and see what's included at what fare levels.

https://www.frontierairlines.com/fro...fairs-chart.do

Now back to the original topic, as obviously the traveler about which the traveler asked is not a frequent flyer on Frontier. The only means of payment is by swiping a credit or debit card in the seatback -- you don't need to engage the flight attendent, and the F/A are not equiped to accept cash. However, I have seen F/A swipe their complementary TV card for minors traveling alone because obviously they don't typcially have a credit card.

If your traveler is an unaccompanied minor, I think it's standard for the F/A to turn on TV for them. If your traveler is young but old enough that they are not considered an unaccompanied minor and are flying alone, I would suggest they have $6 cash and, ask the F/A nicely if there is any way they can buy television even though they are too young to have a credit card. I would guess that it's nearly certain that either (a) the F/A will comp TV for them, or (b) an adjacent passenger with a credit card will help your traveler out (either free or by taking the $6).

I don't know if there is any firm policy to comp (or strictly not to comp) TV for minors traveling alone who would not otherwise have a credit card, but I've seen it happen more than a few times. If your son does not have a credit or debit card, I think it's still nearly certain he can get television onboard one way or another.