You only need to put the lens on the main camera. The dual camera phones have one main camera and one secondary camera. Align the Blips lens on the objective lens of the main photocamera and use the phone as a microscope, or as a camera for macrophotography!
How can you recognize which one is the main camera? EASY! Cover, with your finger or with anything else, each camera; when you cover only the main camera you will not see the previous image on your screen. When you cover the secondary camera, you will keep seeing the same image on your screen (you will not note the effect of the coverage)! Here a short demo video
Diversely than common clip macro lenses, the Blips lenses, thanks to their extra small size, do not cover the secondary phone camera, as well as the led of the smartphone. Therefore, they do not disturb the balancing of the light and the performance of these smartphone cameras.
On some iPhone models (i.g. iPhone X) the image may switch from the main camera to the secondary one, in particular when you apply digital zoom. For avoiding this annoying effect the solution is locking the autofocus, once you are going to apply the digital zoom! How to do it? On the native camera app of IOS, as well as on our free app, it is very easy: just keep pressing on the screen for a while and you’ll get it done.