This study is a multicenter, prospective, randomized controlled trial (RCT) to compare the effectiveness of a smartphone-based self-monitoring and self-management tool on control self-efficacy with respect to standard clinical practice for patients with relapsing-remitting multiple sclerosis (RRMS). RRMS patients will be recruited and screened for study eligibility at four Dutch MS centers. Following inclusion, participants will be randomly allocated to the intervention group (use of MS sherpa® in addition to standard care) or control group (standard care only). The duration of follow-up is 12 months with study visits at baseline and 12 months, and additional study assessments coupled with every clinical visit as part of standard care during the follow-up period.

Inclusion Criteria:

1. Signed informed consent form.
2. Able to comply with the study protocol, as judged by the investigator.
3. A minimum age of 18 years.
4. Have a definite diagnosis of RRMS according to the revised McDonald 2017 criteria.
5. Have a length of disease duration of ≥12 months, from date of MS diagnosis.
6. Have clinical disease activity (one or more reported relapses) and/or radiological disease activity (new/enlarged T2 lesions or T1 contrast-enhancing lesions) within the past 12 months.
7. Willing and able to install and use MS sherpa® on own smartphone with Android (version 4.4 or higher) or iOS (version 9 or higher) operating system.
8. Willing to stay for treatment with the same hospital during the year of study.
9. Willing to follow the rules of conduct as described in Appendix A during the year of study.

Exclusion Criteria:

1. EDSS of > 6.5 at baseline screening.
2. Presence of a cognitive, visual or upper extremity deficit that disables the use or measurements of MS sherpa® on the smartphone, as judged by the investigator.
3. Concomitant use of health monitoring apps or devices for MS during the study.
4. Concomitant participation in another intervention trial in MS.