While to me this just looks like a clever ad for a cellphone business in the form of a pashkevil, it claims the support of rabbonim and poskim for the need.

This pashkevil, the broadside, pasted on walls in Haredi areas (this one specifically in Jerusalem), claims there is a concern for the rpesence of chametz as we always use oru phones around the year and there is no way to keep them clean and form the record of repairs they regularly find chametz int he hones, one should get a new phone for Pesach. So this business is selling rabbinically approved phones special for Pesach. If you get a new clean phone, you will be able to enjoy the Pesach holiday without concern that a crumb of chametz might fall from your phone into your food.

So now the kosher phones hechsher should also say "not including Pesach" as does the hechsher on food items, and there should be a separate hechsher for kosher for Pesach phones....