Here you will find all the information in documents especially prepared for you. You may read them online or download them onto your device if you want to have them handy.
ROAMING configuration Guide
03-GUIA-CONFIGURACIO-SERVEIS-ROAMING
Forced ION MOBILE      network
03-GUIA-CONFIGURACIO-SERVEIS-ROAMING
How to enjoy more than 100 Mbps
01-GUIA-GAUDIR-DE-MES-DE-100-Mbps
                APN Settings for                Android
02-GUIA-CONFIGURACIO-APN