Here is another Bluetooth energy board for your projects. The Adafruit Feather nRF52 Bluefruit LE is compatible with Bluetooth. It comes with 19 GPIO, 8 x 12-bit ADC pins, and 12 PWM outputs. The board comes with an ARM Cortex M4F processor, 512KB flash, and 64KB SRAM.
The board measures 2.0″ x 0.9″ x 0.28″. You can use the Bluefruit iOS/Android app to get started.