Improper authorization in handler for custom URL scheme issue in 'Skylark' App for Android 6.2.13 and earlier and 'Skylark' App for iOS 6.2.13 and earlier allows an attacker to lead the application to access an arbitrary web site via another application installed on the user's device.
https://play.google.com/store/apps/details?id=jp.co.skylark.app.gusto