Works great on my Sony smart TV, but i know lots of people having issues with LG sets. There was also a streaming hiccup with the first live match shown which effected all platforms, and didn't help.
But honetly, I have not used since the live match. I may go on today to check post-match stuff, but most of the things I could see on there are availble on youtube anyway. Where it can differentiate itself if with showing live games from the EDS and womens game, maybe the odd mens game if licensing allows, and fast upload of match highlights. Maybe also transfer reveals first, given 'tis the season right now. £1.99 isn't a lot, but if I don't use it more in the next couple of weeks i'll likely cancel.
City did promise more supported platforms in the near future but no idea on which or timescales.