The 737-8/9 fleet is rapidly being equipped with in-flight internet but it only works over the CONUS. Expect no coverage (even if the plane is equipped) on the IAH-Costa Rica flight and for only part of the SJO-EWR flight. It is not free.

If there are TVs on the plane - the newest 737-900ERs do not have them - then the content will be free in F. Stored movies only outside of the CONUS service area, not live DirecTV.