The Particle Xenon is a low-cost mesh-enabled development board. With the Nordic nRF52840 SoC you have all the power of an ARM Cortex M4 with OpenThread mesh networking, NFC, plenty of GPIOs, LiPo charging and more. The board is designed to act as a standalone endpoint or repeater in a Particle Mesh network.
The Xenon is also configured in the popular Feather footprint and so is compatible with Feather Shields! That means it includes a JST connector for a Li-po battery as well as charging of the battery over USB. Particle also provides an RGB status LED and a JTAG (SWD) connector for debugging and an onboard PCB antenna for your mesh network.
The Xenon comes with access to the Device Cloud (10 free micro networks available) as well as three free months of device Cloud access using a cellular gateway. The Particle Could has some great features for building connected projects, including over-the-air firmware updates, and easy-to-use REST API, and firmware development supported by web and local IDEs.