Current software version is 1.5b2 (alternate download link). You can check your version on the status screen by opening 192.168.10.1 (no www) on a web browser of a device connected to the stratux WiFi network. Software images are posted on stratux.me website.
Updating involves removing your SD card. You can use the video instructions or follow text instructions.
Spare SD cards with adapters can be purchased from Amazon for $3. You can also purchase a SD adapter for flashing. Preflashed cards are also available.
CAUTION: SD cards are easily damaged. Take care not to bend or pinch them when removing with tweezers.
NOTE: Any SD card greater than 2 GB will work.