I have just added another very small form factor called the "Feather" Nordic Semiconductor nRF9160 Bleutooth Low Energy (BLE) PCB module which is based around the Adafruit "Feather" design :

This is in addition to the "Thingy" small BLE project and nRF9160 evaluation module :

As well as the Nordic Semiconductor full development platform PCB :

Each form factor and functionality is useful for various purposes similar to the Raspberry Pi standard card and the slimmed down version called the Pico, which has a minimal size for reducing space when integration into a larger design is important.
I invite you to check all of them out and let me know which is your particular favorite.