I went there this week. It’s at the second last subway stop of line 1 in the south.
The pool is not open yet, but you can go in for free now to have a look. There’s also a ice skate ring on the top floor (normal size) and of course an IMAX theatre beside loads and loads of shops. In August a huge Korean brand shopping mall will open (Latte?) which will use about 1/4 of the whole building.