If you really want to get rid of reflections, get more contrast, and see true colors - you just can't go without a polarizer! Now that the phone cameras are so advanced,
SandMarc iPhone ND filters & Polarizer, Photography, Photography Accessories, Other Photography Accessories on Carousell
Clip these filters on your iPhone for truly striking images | Cult of Mac
SANDMARC Drama Filter + Lens Case - Sandmarc - Touch of Modern
iPhone CPL Filter - SANDMARC
Sandmarc launches Kickstarter for smartphone polarizer and ND-filters: Digital Photography Review