I have a JJRC H68 Bellweather, and I was myself able to connect with a phone.
However, the frame rates were so terrible and choppy to the smart phone it was absolutely unusable to fly to... we're talking like... maybe... 3-10 frames per minute? Worse, in the bright sunlight, it's hard to read the screen. You can forget pretty much trying to control the quad using the app. That was my own experience.
Just forget about trying to connect and fly it that way, flying it using your smart phone was just a gimmick to sell the quad. It is for all quads IMHO, you really DON'T want to fly them this way. The video feed if it worked when it worked would only be useful to hand to a spectator to watch while you flew line of sight.
Your best bet is to fly it line of sight (or blind) using the the controller in Angle mode and with GPS lock on, and just go up and down like a weather balloon on a string, and yaw around to take photos or video saved to the microsd card. The GPS lock on the JJRC is actually very good and a feature most high end freestyle quads don't have, so take advantage of it. The gimbaled camera on it is only good really for recording video and viewing it later on your computer, not flying to. I got my first videos that way.
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However, you can buy a cheap analog "All-in-One" camera (from alixexpress or banggood) for under $20, a 1s battery to wire it to, with a switch, and hotglue it all to a piece of cardboard and rubberband or tape that to the top of the quad at zero degrees camera angle pointing straight ahead. All-in-One Cameras have the camera, 5ghz analog video transmitter, and antenna all in one small package, and you can identify them when shopping by the antenna sticking up from the top of the camera.
A pair of mini analog goggles can be had for $35, or any analog goggles. You'll fly via looking through this viewing the video signal put out by the All in One camera you added on top of your JJRC.
I flew mine around like this for one flight into a tree where the props got stuck and I smoked the brushed motors almost instantly. So it does not make a good quad like that, but I did indeed fly it FPV at 60 frames per second with a usable FPV feed.
You can then move your cardboard all in one camera mount over to any other thing you want to FPV, like another quad or RC truck, etc.
JJRC H68 Line of Sight Flying Tower (original stock gimbaled camera footage):
JJRC H68 Line of Sight Flying Panorama Look Around (orginal stock gimbaled camera footage):
Your best bet for footage capture is to make no movements at all, just up or down... or as slow and gentle as possible. Also be slower coming down than up, as as you can see in the footage, when it goes through it's own propwash on a straight down decent it wobbles like crazy.
Attached picture is of an aftermarket All-in-One Analog FPV camera/transmitter/antenna unit that can be added to anything to "FPV" it, pair with any analog FPV goggles.