A computer, laptop, or phone does become a mushaf (copy of the Qur’an) simply by having an app in its memory. Therefore, you can hold that device and take it into the bathroom, which you cannot do with a mushaf. However, when the app is open on the screen, you are not allowed to touch the Arabic verses of the Qur’an with your finger or mouse pointer, but you can touch other parts of the page or the English translation. This is similar to touching a piece of paper with some verses of the Qur’an on it where you must not touch the Arabic verses but can touch the translation or margins of the page.
Shaykh Mustafa Umar