Major players on the back side of the motherboard (gigantic version):

Qualcomm PM8028 RF Power Management IC

Atmel TINY45 8-bit RISC-based Microcontroller with 4KB in-system programmable flash

Toshiba THGBM2G8D8FBAIB 32GB eMMC NAND Flash

Kionix KXTF9 MEMS Motion Sensing Accelerometer

ST Ericsson CPCAP 2.2TC22 DC Power Management

According to Chipworks, the CPCAP 2.2TC22 is a single chip SoC that integrates analog and mixed signal functions, including power management, energy management, audio, and interfaces.

Check out the die photo of the CPCAP 2.2TC22, courtesy of Chipworks.