Jack's Rooftop bar is situated nearby the Tianjin TV Tower, which makes for great evening views. This is a spacious rooftop bar with plenty of seating available. The drink options are decent and the price is what you'd expect for the venue. Overall, there's a nice atmosphere and if you're with the right company, I'm sure you'll have a good time.
The bar can be a bit awkward to get to - I think the only access was by elevator.