The MyTherapy App (https://www.mytherapyapp.com/) is promoted as a medication reminder and tracker app but it can be handy for so much more. You can add one-off entries for medication, measurement (think blood pressure, blood sugar), lab values (blood test results), activity or symptom check (fatigue or pain scale anyone?).
Better yet, set up a schedule and this app will politely nag you until you confirm you’ve taken the meds or measurement, done the activity or recorded your symptoms. If you are busy at the time, you can “snooze” or “skip” the activity. For medication, you can also set a reminder for refilling a script when you get down to a set number of tablets.
One of our contributors found it very useful for remembering to do their physiotherapy exercises (rather than forgetting until they receive the reminder for their next appointment). The app is free to download and does not require you to create a user account.