There are two separate versions of the app available : Foobar2000 Copilot Lite (free) and Foobar2000 Copilot (paid, but also with a free trial)
Foobar2000 Copilot Lite
This is the free version of the app and is available in the Microsoft App Store. The only differences between it and the paid version of Foobar2000 Copilot are that : 1) it includes one AdDuplex cross promotion ad at the top of the Search page. There is no other banner ad in the app. 2) the flashlight feature was removed.
Foobar2000 Copilot
The TRIAL version is the FREE version -- since there is NO TIME LIMIT to the trial version, and the trial and paid versions are exactly identical in features, except for the displayed advertising banner in the free version.
Buying the paid version will remove the advertising banner from the application.
Foobar2000 Copilot v1.3.0.0 has only one advertising banner -- that banner is located at the bottom of the 'now playing' screen. See the following images of what that screen looks like with and without the banner ad.
FREE version (with banner ad)
Paid version (no banner ad)
There are no additional features in the paid version.
The choice is entirely yours, enjoy the application either way.