Bluetooth based Sensors to the Cloud, processor choice?
Based on https://developer.relayr.io/documents/WunderBar/MM its clear they didn't want to design a wifi module from scratch, so they used an off the shelf wifi module, that handles most of the wifi &amp; tcp-ip overhead, and is FCC certified for modular usage. It reduces their coding and manufacturing overhead. They use a Freescale K series ARM chip for encryption, and translating the raw sensor data. The BLE chip again seems to be used for offloading any Bluetooth operations.

Had they used a Freescale KW instead, it would have to be able to do both the standard WIFI, TCP-IP, SSL requirements, as well as their own code. And they would have to design a board, likely multilayer, with 802.11b/g/n RF considerations, antenna choices, shielding. Then they would have to get it tested with the FCC. Iron out bugs. The costs probably exceed any benefit.

As to why they didn't use something like the KW30Z, a Kinetic with BLE IC, that's just a guess, but maybe they got better support or a pre-built firmware for the Nordic than they would have with Freescale? It does seem to be almost double what the KW30Z would be, which is only 20 cents more than the existing MK22FN512VDC12, but looking at the specs, the K22 microcontroller is 120MHz with 128KB Sram and 512KB flash, while a comparable BLE Kinetis microcontroller is only 50MHz/20KB/160KB. They obviously needed more power from the microcontroller than using a single IC would have allowed. So they went with a bigger (and more expensive) IC because of processing needs.