Several of the following things can happen:
- You lose your phone
- Your phone auto-upgrades itself and loses apps and bookmarks
- Your phone breaks
Therefore it is always important to make a backup of your easywallet.org wallet. You can find the wallet URL as a QR code from the main site if you scroll down. Just store the URL to couple of separate locations, and you should be backed up.
Additionally it is always a good idea to set up a Dead Mans Switch, just in case.