In the design phase, persuasive elements should be added to the prototype to increase its effects. Examples of models that can be used to add persuasive elements are the Persuasive System Design (PSD)  and BCTs .
Persuasive technology is technology that is designed to change attitudes or behaviour . To achieve this, persuasive elements should be added to the prototype during the design phase. Most eHealth technologies aim to influence specific behaviours or cognitions. Consequently, Behaviour Change Techniques (BCTs) can be added to the design as well, especially since research has shown that more extensive use of theory in technology results in increased effects . BCTs are derived from behaviour change theories from psychology and can be defined as a general technique to influence or create changes in the predictors of specific behaviour.
 Oinas-Kukkonen, H., & Harjumaa, M. (2009). Persuasive systems design: Key issues, process model, and system features. Communications of the Association for Information Systems, 24(1), 28.
 Michie, S., Richardson, M., Johnston, M., Abraham, C., Francis, J., Hardeman, W., . . . Wood, C. E. (2013). The behavior change technique taxonomy (v1) of 93 hierarchically clustered techniques: building an international consensus for the reporting of behavior change interventions. Annals of Behavioral Medicine, 46(1), 81-95.
 Fogg, B. J. (2009). A behavior model for persuasive design. In S. Chatterjee & P. Dev (Eds.), Proceedings of the 4th international Conference on Persuasive Technology (Article No. 40). New York, NY: ACM.
 Webb, T., Joseph, J., Yardley, L., & Michie, S. (2010). Using the internet to promote health behavior change: a systematic review and meta-analysis of the impact of theoretical basis, use of behavior change techniques, and mode of delivery on efficacy. Journal of Medical Internet Research, 12(1): e4.