I have an app for android "River Brain Flows" (Apple rejected the IOS version). The sites new look and feel works good for mobile and tablet viewing on any platform.
River brain has USGS, CDEC, CDWR, some CANWO and AHPS where it can make the match. All gauges updated every 15 minutes. Any river listed on the site is available on the mobile platform (as well as any future river info added will automatically start showing up), favorites, info, etc.
As far as pros and cons you guys can make the call on that.