You can achieve this effect on an iPhone using two techniques, each with its own strengths and weaknesses. Bokeh is the name given to the out-of-focus blur that appears in the background of a photo.

Photoshop CC tutorial showing how to make a great-looking bokeh background and bokeh text effect. ➤ Get 15% off BORIS FX ...

Pronounced "bo-kay," the bokeh effect refers to the out-of-focus background in a photo or video. Depending on camera type and distance to the object in focus, the bokeh effect is often ...

Bokeh is a photography term that’s a bit difficult to define but is basically soft, aesthetically pleasing background blur, often used to make a subject stand out. Also called “background ...