I'd also read that topic last time and I also create one on our local board asking for feedbacks wether it is safe or not.
It's not safe. I downloaded and installed and then realised that it only wants to capture your login details.
I immediately change my password after that.
Same, this is only for hack purposes. At first i didn't think about it as a hack because it's look legit and similar to the site. Until i realized that it's impossible to have a mobile app of this kind of forum and i know that this is exclusive for web browsers only. I change also the password of mine because it might hack my account.