This app is as ugly and in intuitive as they come. Once you figure it out it will work though.
First make sure your BlackVue camera is supported. You cant connect if your camera doesnt support WIFI (and you connect to its network)
The menu at the top has additional options if you scroll left/right. I didnt notice that for a while.
Cleanup the interface, use high res images, and implement proper iPhone 5 support (use the entire screen) and I will rate it higher. In the meantime this looks like it was just thrown together and it shows.
franklam about BlackVue Legacy, v1.002