What can I say about gmail that no one knows? Its probably the first thing we used on the internet. Googles very own email client which has more than billion users.
App is very small in size and does all the functions of gmail that can be done on the web. Its easy to access. The best part is how it categorizes all emails into different categories like social media, primary, promotional etc etc.
The app makes the experience of gmail even smoother and better than the web.