Being physically active is known to have significant benefits for health and wellbeing. Wearable accelerometer-based devices have become very popular in consumer applications, and they are also used widely in research. They can also be used for motivating the user for being physically more active. Mobile technologies and gamification have demonstrated potential for personalized activation services, but there are also challenges in sustainability. This presentation overviews some approaches for assessing physical activities and sedentary behavior, feasibility of gamified physical activation solutions, and perspectives for promoting health of older people.