development kit

Hi, I want to develop a key finder that works via bluetooth and rfid, the device should be able to connect with a smartphone app. An example of such a product is Sticknfind product on youtube or flylinktech mini keep key product. any suggestions on which development kit works best? If there isn’t one, where can I find such a development kit?

Arduino only sells one kit. (Starter kit). Did you mean which uC ?

Bluetooth Low Energy development kit