Does anyone know what wallet can keep Siacoin? or you guys just leave it on the exchange?

Are there any Android app for bitcoin to altcoin exchange? So that I can do some trading on my phone.
I have check polo bittrex but they have to log in to a web browser. It wouldn't be convenient for me to keep logging in to polo when I'm in office. My boss will kill me. Lol.
I know jaxx wallet have built-in shapeshift but their altcoin is limited. Any advice is appreciated