Easy phone play online

The purpose of the application is to allow all people to make calls in a simple and intuitive way. After an initial configuration phase of the contacts and settings, it will be possible to initiate a call by simply pressing the image of the desired contact. Among the various configurations available to the user there is also the possibility of automatically starting the conversation always in hands-free mode.
After completing the contact selection phase, access to the contact details can be disabled from the settings, in order to prevent the end user from accidentally making changes to the contact data.

Any suggestions that can improve the usability of the application in order to make it really useful for someone will be very welcome!