If you are willing to take a risk: VR BOX, a viewer that (possibly) provides 95° - 100° FoV for 6" phones, available for less than USD 25 : r/GoogleCardboard
VR BOX 2.0 Virtual Reality 3D Glasses for 3.5-6.0 inch Smartphone; and – Dukakeen
THE ONLINE SHOPPING CASH ON DELIVERY: VR BOX Virtual Reality 3D Glasses for 3.5- 6.1" Phone (White)
VR box: Buy Online at Best Prices in SriLanka | Daraz.lk