I saw these advertised and thought the price was good and I should give them a try, as I was trying to find a good sound interface for my computer.
They work well to record sound, however, I found it irritating to have to keep using the app to set up the gain (should really have some kind of gain control). I found that it made a great mixer for playing electric guitar, since my effect pedal had no input for mp3, I could use the Bluetooth feature on the Flow for this.
I ended up getting another different interface and also a pair of monitors. This lead to a new problem. My monitors couldn't be plugged into both interfaces. So I solved this by using one of the stereo channels on the flow to connect to the output of my other interface.
Now the Flow mixer has become an integral part of my studio, and I love how it works, as it allows me to quickly connect any input to my monitors.
Would recommend one as they are very useful.