No, unfortunately it is technically not possible to accurately measure one's blood pressure via the iPhone (e.g. by using the iPhone camera). Blood Pressure Assistant can just be used for manual logging of blood pressure readings.
If you do not own a blood pressure monitor, good ones are available here:
- Germany: http://amzn.to/1PcxrpV
- UK: http://amzn.to/1Q6NlV4
- France: http://amzn.to/1GLxNle
- Italy: http://amzn.to/1bJzWTz
- Spain: http://amzn.to/1Ivf6UU