Keep your mobile phone updated
It is important that you periodically check that your phone has the latest system updates installed.
Whether you use iPhone or Android, it's a good idea to periodically ensure that your phone has the latest system updates installed.
The manufacturer regularly sends out updates for necessary performance improvements, bug fixes and security updates. Recently, for example, Apple sent out a new update of ios that is recommended for all users.
On the iPhone, check this by going to Settings / General / Software Update. If you are an Android user, you can check the path for your particular phone model, but they are usually found under Software Update / System Update in the phone's settings.