Why: Simple, thin and sturdy, fits like a glove, soft plastic does not wear down the sandstone material unlike some hard plastic and metal cases. Black color does not show wear and jeans color.
Screen protector: iLLumiShield Japanese Ultra Clear HD Film with Anti-Bubble and Anti-Fingerprint
Why: Best plastic screen protector I've ever used, cleaned screen with alcohol pad, dried with microfiber cloth, made screen squeaky clean with included cloth, lined up speaker grill and and camera and just let go. Perfectly cut, no static, no dust, no air bubbles, more oleophobic than the OPO's Gorilla Glass.
OTG/USB MicroSD card reader: OTG to USB Micro SD Card Reader for Samsung Galaxy S2, S3, S4, Note 3, 8 Tab 3
Why: Very small, versatile, good build quality, only $5. Tested with 32GB SDHC.
Earbuds/Headset for Android: Sony MDR-XB50AP Extra Bass Earbuds
Why: Best sounding earbuds I've ever owned, emphasis on bass without compromises, microphone and Android compatible.
Travel charger: Anker« 2nd Gen Astro3 12000mAh
Why: Great build quality and design, comes with pouch and USB cable, actually lives up to its battery specifications, unlike many other brands. 6000mAh and 9000mAh variants are also great and affordable.