I would love to see the RtL app incorporate a LoS calculator. The app already knows what map tiles exist and the 3D map is already clickable for tokens and doors. The only information that the app needs is the source square and target square (or squares for large monsters) and any additional blocked squares. My thought would be to enter a LoS Calculation mode where the user is prompted for the source, target and any blocked squares. The app would then draw any successful LoS in green or a "No LoS" message if there is no LoS. I understand that there can be exceptions with some class cards but this must be understood by the players. This would be GREATLY helpful for those of us who find calculating LoS quite difficult depending on the situation. What does everyone think?