I had gotten this old school make of protector by Spigen and it works with Magpul, Zoogue, Apples leather case and even UAGs case. Amazons title is long and descriptive:
iPhone 6 Plus Screen Protector, Spigen® [Full HD] iPhone 6 Plus (5.5) Screen Protector [Crystal Clear][3-PACK]**JAPANESE BASE PET FILM** High Definition (HD) Premium Ultra Clear Front Screen Protector for iPhone 6 Plus (5.5) (2014) - Crystal CR (SGP10873)