As you're doing it in 3D space, then you'll have to adjust your camera settings based on the device/resolution the user is running.
For example an iPhone5 resolution is a widescreen style display, as apposed to an iPad1 which is a 4:3 1024x768, so you'll miss the 3D space that's on either side of the screen.
I would suggest you do a windows standalone build, and use the "Screen Set Resolution" action to switch between the range of resolutions you want to support. Add them to a key press so you can quickly cycle between them, and you'll be able to easily see how Unity cameras handle each one.
I guess you'll probably end up needing to modify the camera FOV and/or position slightly based on device/resolution to make it look right.