UPDATE REVIEW: The customer service of MIOPS is outstanding. I have had several exchanges and each was both prompt and very productive. Previously I had written about the lack of a focus capability in the software control. Within a week, the company updated the software and the capability now works and works well. The focus is similar to that by the NIKON software of touch to choose the focus point. The response time is perhaps 1-2 seconds but not a significant issue for the applications where is FLEX is used. I'm impressed by the hardware, software, and especially by the people at MIOPS.
EARLIER REVIEW: I actually would give the customer response a 5 star rating. I find the responses prompt, very helpful, and informative. The three star rating is because the Flex App does not allow focus adjustment. I have a Nikon D850 with some Nikon lenses. Without the ability to focus with the app, like is possible with the Nikon IOS app, capturing the photo properly is tedious in many situations. The customer service response recently stated, "Regarding focusing, we will release touch focus option soon." When this happens, I will give this device a 5+ star rating! The Flex has lots of potential for my applications.