You need a Wi-Fi connection and it is best to have a high battery level on your tablet. (Better still, leave the device charging overnight.)
For iPad or iPhone, you also need to ensure you have auto download content ON for the Independent Daily Edition in your settings. To do this, tap on the Settings icon on your device screen. In the menu column on the left you’ll see GENERAL. Tap this and in the right hand column look for BACKGROUND APP REFRESH. Tap this and scroll down until you see the Independent Daily Edition. Slide the button to the right of the Independent Daily Edition app so that it appears green.