What all file types can we transfer from an iPad to Sandisk iXpand 3.0 using a native app?
Is there any file size limit?
what native app are you referring to? many are different however if the native app support the share extension then you can share the file from the app to iXpand drive. if not you can use the open in feature of iOS. Those are really the only 2 ways to share data between two apps in iOS.
