HiLO Lens is great for candid photos, below are some tips for street photography with the HiLO Lens.
One way of holding the phone with HiLO Lens is at hip level, then look down at the screen while the camera is directed away from you by the HiLO Lens. This shooting position is similar to the classic Brownie camera. The direction we look attracts attention, if you are looking down at your phone people will pay less attention to you.
Another way of holding the phone with HiLO Lens is in a comfortable position for viewing the screen with the HiLO Lens redirecting the camera to the right (or left if you hold the phone upside down). Because your regard and your body is not aligned with the scene you will attract even less attention.
If you hold the phone at a comfortable viewing angle then it will be tilted. With the HiLO Lens attached and facing the right this rotates the scene. It is possible to rotate the preview in the HiLO Lens app to correct for this. In the HiLO Lens app options turn on Gesture Support > Rotate. Then a two finger rotation gesture will rotate the image for preview. I find the easiest rotation gesture is to place my index finger and thumb tips on the screen then twists like taking the cap off a bottle.
You can also turn on the HiLO Lens app option Gesture Support > Pinch so that a two finger pinch gesture will zoom in. The combination of the pinch and rotate can help frame the scene. When touching the screen to perform a rotate or pinch gesture the separated focus and exposure controls may be shown. You can reposition these icons to set the focus and exposure or single tap the screen to set the focus and exposure at one point or double tap to enable continuos auto focus.
The HiLO X Grip case allows the HiLO Lens to snap fit and swivel in place. This helps to change the camera orientation without drawing attention.
Be sure to know the laws regarding public photography in the country where you are. Also be aware of the local culture in regards to photography. In many places street photography is a recognised and appreciated art form but that is not the case in every country/culture!