Between young people in the Arab world, texting and social media like Facebook and applications like WhatsApp are commonly used instead of email to plan an outing or meeting. However, it is culturally inappropriate to only text an older person to set up an appointment. Calling an older person (friend or acquaintance) or a manager (in a work setting) is more appropriate for any kind of communication.
The concept of time is more fluid in the Arab culture where parties can extend for hours; showing up on time is not very common. This is why it is important to have a cell phone to check if the person is on the way to the meeting place or not, especially in big cities where traffic can be an issue.