Bosma Sentry Video Doorbell:
On the Bosma app, go to Event History and play the recording you want to download. On the playback page, there should be a download button at the top right corner of the screen. Tap that button and the recording will be downloaded to your phone.
All Bosma Security Cameras and Video Doorbells:
Remove the SD card from your device, then use a micro SD card reader to read the SD card on your computer. You should find all recordings in the SD card grouped by date.