Is it permissible to read the Qur’an from a phone instead of a printed muṣḥaf?

Yes, reading from Qur’an apps on a phone is permissible, and the reciter is rewarded for it just as he is rewarded for reading from a printed muṣḥaf; for what matters is the recitation of God’s words and reflection upon them, not the medium through which they are read. Indeed, reading from a phone may be easier in many situations, for the Muslim carries the Book of his Lord in his pocket and so recites it on his way, at his work, and while he waits — scarcely does an idle hour pass him by without his having a portion of the Qur’an within it.

There is, however, a subtle juristic distinction that ought to be made clear: the printed muṣḥaf, according to the majority of the scholars, may not be touched except in a state of ritual purity from minor impurity, taking guidance from the words of the Exalted: "None touch it except the purified" [al-Wāqiʿa: 79], and from what is reported in the letter of ʿAmr ibn Ḥazm, that the Prophet ﷺ wrote: "that none should touch the Qur’an except one who is pure" — a hadith whose chain is disputed, graded ḥasan by more than one scholar through its combined routes. As for the phone screen, it is not a muṣḥaf with respect to the ruling on touching; for the letters appear and vanish, and are not written and fixed like the pages of the muṣḥaf, so it is permissible to read from it and to touch it for one who is not in a state of wuḍūʾ. In this there is a clear ease, especially for one who is moved to remembrance at times when he can find no water.

Yet the printed muṣḥaf retains its merit and its special quality: in gathering the heart, and in the fewness of the notifications and messages that distract and cut off the reciter’s humility. So it is best that the Muslim allot himself a share of this and a share of that; reading from the phone when need arises, and returning to the muṣḥaf in his seclusion and reflection.

In sum: read from whichever is easiest for you, and let your concern be the humility and presence of the heart, for the aim of recitation is that the verse carry you to its intent, not that it merely pass over your tongue.