Yes, you can download the BeRebel app on multiple phones and access it via the phone number already registered and the otp received on the mobile number associated with the contract.
For example: my dad is insured BeRebel, I am the son and I later downloaded the BeRebel app on my phone. To see my father’s policy, on the first access to the app, I entered his phone number and the otp code received a few minutes later to his number.