The Examen is a prayer of review - a short reflection back over the day, recalling events and taking note of your feelings.
The purpose is to become more aware of the ways in which God has been present to you, the times when the Holy Spirit was drawing you towards life.
Although coming from an older monastic tradition, St Ignatius recommended it to his earliest followers. It was the key prayer for Ignatius. When early Jesuits found themselves too busy to fit in all their usual prayers, Ignatius gave them permission to pray less, but told them to keep up the examen.
 Examen is Spanish for examination, an examination of your day and how God was at work.