Q. 1) The other day, I ended up daveing mincha in a room where the lights went out., so people started daveing from the siddur on their phones. My question is, should they kiss their phone when they finish davening, as they would do with a siddur? If their phone dropped while davening from it, should they kiss it? (while the words of the siddur are still on the screen).

Q. 2) Could you enter a bathroom, without turning off the screen?

A. 1) On question 383 we wrote: “Most Poiskim rule that Hashem’s name written on a screen can be erased and they have no sanctity as the pixels which make up the letters on a computer screen are being refreshed many times a second and are considered to be more virtual than real. T’shuvos Vehanhogos (3: 326) permits erasing Hashems name adding also the fact that it was not written with the intention of kedusha. He also points out that s’forim like chumashim and sidurim, are commonly printed today by using computers and so are the very effective and essential programs to check the kashrus of sifrei Torah and tefilin. So too is lenient Avnei Yoshfe (4: 105) and Nishmas Shabbos (Mechika Uksiva 137).and others (see Piskey Teshuvos 174) However some Poiskim are more stringent, Shevet Halevy (7, 4) rules that even though erasing a name written on a screen is not biblically prohibited one should avoid doing so only in cases of great need, a similar opinion is to be found in Sheilas Shoul (Y.D. 59: 3). Horav Shlomo Miller’s Shlit’a opinion is that it is permitted to read Torah and Tefilos with Hashem’s name from a screen when needed, but one should always do so with decorum and kedusha.”
Following the above, Horav Shlomo Miller’s Shlit’a opinion is that a phone used for davening, since the words screened temporarily are not considered writing, does not acquire any sanctity, therefore it is not given the love and respect given to a chefetz shel kedusha and should not be kissed when it falls.
Consequently, the Rov advises that people should rather when possible daven from a siddur that has a degree of kedusha and not from a phone.

A. 2) However, as mentioned above, while the words are on the screen, it should be treated with respect and not be carried inside a bathroom or similar.

Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit”a