Please tap on your more menu and tap 'Settings'.

Tap 'Medisafe Premium' (Manage subscription)

It will then take you to the Play Store and you will see an option to cancel your subscription.

Open the Play Store

Open the side menu (3 lines in the search bar)

Tap "Subscriptions". You will find Medisafe here and be able to unsubscribe.

Open the Settings app

Tap on 'App Store'

Tap your Apple ID on the top right corner

Tap 'Subscriptions'

Then tap on Medisafe. You can then cancel your subscription.