FL Studio mobile works on iOS, Android, Windows and any Chromebook on the market.
It comes with a great autotune for less than 15€ and makes it possible for anyone on a budget to get a decent sound with minimal effort.
I still have my Waves vocal chain for recording in my DAW, but at my level of producing I don't really need it.
Pro Tools is great btw - I just have a screen resolution conflict because I use Windows 10 Pro on a tablet (Surface Pro).
To anybody who hasn't given FL Studio mobile a try it might be a good option for artists that can't get to you for a vocal session.
They can get a microphone and interface for their bedroom setup, or make use of a USB microphone like I do for all voice recording.