Carrying a Mobile Phone on Shabbat
Question
Is it permissible to move a mobile phone on Shabbat if it was accidentally left on the Shabbat table, and if so, how?
Answer
A mobile phone in our times is considered a utensil whose primary function is prohibited on Shabbat (“melachto le-isur”), and not as something a person guards because of its value (“chisaron kis”). The reason for that is that one may handle it, for example, to place it on papers so they won't fly away or use it as a bookmark for reading a book, etc. Therefore, it is forbidden to move it when the intention is to preserve it from damage. However, when one wants to use it for something one is allowed to do on Shabbos, for example, to put it on top of pages so they won't fly away in the wind, it is permissible. And the same goes for the case when one needs to clear the space where it is located: this is permitted.
Source
Shulchan Aruch (Orach Chaim, Chapter 308, Paragraph 4).