Various tile colours (In wall view mode. blue = dora indicator, green = tiles you will draw and orange = dangerous tiles)
You can view only view the walls from games that were played after 8am on 03/02
I’ve played on a lot of mahjong clients and the only other client I’ve seen with the ability to look at the wall in replays was Marujan but that client just isn’t worth the enormous price it costs to actually play there.
I just noticed Tsuno has added some shuugi test play games but they seem to be windows client only at the moment.