I don`t think it is worth the risk of getting hacked through a phone app. The thing is hackers can easily make a similar Steemit app and put it on-line to install. Once they sustain your password it will be game over for that Steemit account. If I am dealing with crypto I will do it from my laptop. I even bought another laptop that I just use for my crypto wallet and nothing else. So it makes my crypto wallet far more secure since I do not use my laptop for any internet surfing except for my wallet.