the Fatwa Department Research Committee - chaired by Sheikh `Abd al-Wahhâb al-Turayrî
Such devices do not take the same ruling as a printed Qur’ân because the text has to be interpreted from a different format before it can be read. The format in which the text is recorded is a digital format that needs to be interpreted by a specific program in order to be displayed on the screen in a recognizable character set.
Bear in mind that this digital code only displays the Qur’ân in conjunction with a compatible program. Without that program, the code will not display the Qur’ân on a screen.
Therefore, you may carry such a device without being in wudû’.
And Allah knows best.
Source: Islam Today