Hey friends I am a daily user of Gmail as it is very necessary for us to share or to mail something through a trusted circle.
Help and functionality : helps us a lot without it it would be very tough to manage or survive on networking.
Ease of use : great ease of use you can directly mail anybody or a specific organisation.
Ease of installation : very easy and free from play store or many of a times is inbuilt in your phone.
Features and functions : it is fulfilled by every feature and here you are not going to compromise for anything.
Service and support : I think you will not need for any support and if you need then Google is always with you.
Thanks.