There are many useful apps and websites available, some recommendations:
Untire Now: for cancer-related fatigue. A common problem (80% of cancer patients and 30% of cancer survivors) and for them a major issue with a significant impact on quality of life. Untire has been shown to lead to lower fatigue and higher quality of life (based on 3 RCT studies).
Vertigo Training: for dizziness. Developed by Amsterdam UMC. Research has shown that 4 out of 5 people become less dizzy by using the app.
URinControl: for (the fear of) urinary incontinence. Developed by UMC Groningen. This occurs in 1 in 3 women. In general, within 2-3 months of using the app, there is better control through muscle training.
The website of the Radboudumc Expertise Center for Mindfulness (specialized in the application and scientific evaluation of mindfulness-based interventions in healthcare) is also highly recommended for (free!) training: body scans, meditation, and breathing exercises. See: Audio files – Radboudumc