This is a clinical study to improve the regularity of medication intake for high blood pressure. Adult women and men who are over 50 years old, who have received a prescription drug for high blood pressure from MediService, and who have to take at least 4 tablets per day (of which at least 1 dose of medication per day is for high blood pressure) can participate in this study.

The investigators intend to examine whether Collabree, a mobile phone application, is effective in supporting patients with hypertension to more successfully following their therapy plan in order to improve the regularity of medication intake.

The study includes a 90-day intervention phase and a 90-day follow-up. The study does not require any therapy adjustments and no visits to a study center are necessary. The participants conduct the study independently at home. Participants will also fill out questionnaires.

Participants are randomly assigned to one of 3 groups in a ratio of 1: 1: 1. Two of these groups will receive the Collabree mobile phone application.

Inclusion Criteria:

1. Informed consent as documented by signature.
2. Over 50 years of age on date of randomization.
3. Patient received prescription medicine against hypertension by post from MediService.
4. Prescribed a therapy against hypertension consisting of 4 or more tablets taken per day. At least 1 dose of medication per day must be against hypertension.
5. Participant administers their own medications.
6. Participant owns a smartphone with a data plan or constant internet access during the study reporting events and at home to use the application.
7. Minimal required smartphone operating system is iOS 12 and Android 8 (Oreo).
8. Adequate communication in German or Swiss-German (all study documentation will only be set to the German language).

Exclusion Criteria:

1. Inability to operate a mobile phone and the Collabree application.
2. Inability to follow the procedures of the study, e.g., due to language problems, psychological disorders, dementia, etc.
3. Enrollment of the Sponsor-Investigator, their family members, employees, and other dependent persons.
4. Participation in another interventional clinical trial.