Segunda Línea is a free Android app created by Movistar España. It allows you to have two phone numbers associated with your SIM card, so you can use the second number to communicate with people without giving them your primary number. When someone calls or sends an SMS to your Segunda Línea, you will receive the call or SMS on your phone with the prefix 22 followed by the caller's number. You can also call with your Segunda Línea directly from the app, which automatically adds the prefix 22 before the destination number.

This app is ideal for those who want to separate circles of trust or protect themselves from phone spam. With Segunda Línea, you can give your second number to companies, temporary contacts, announcements, and contests instead of your main line. You can also customize greetings and deviations for your Segunda Línea, block unwanted calls and SMS, and manage your contacts, all while keeping the same rate as your primary line.