LetterBoxD to JutWatch Filter is a tool that allows you to determine which movies from a LetterBoxD list is available to stream or rent based on the services you're suscribed to (or the ones you're willing to pay for).
Available as both a minimal cli and a gui version
Right now it searches the movies using the french JustWatch version, but an international version is on the way too.
Feel free to make any contribution / raise issues