iphone photography

I'm considering purchasing an external lens kit for my iPhone to help improve the quality of my pictures and video, but first I'd like to get your opinion. Are they useful? Do they make big different in terms of quality? Can you get nice bokeh with them? Stuff like that.

I have an external bluetooth keyboard and when I pair it with my phone, the volume key on the keyboard triggers the shutter release and the escape key closes the app, other than that, nothing else does anything. I was thinking about trying to use it to fire off photos, so I was hoping there...