If you want to have a better performance with Gmail for your mobile, try adding a shortcut to your home screen of your device ( This function never supports all devices). This shortcut creates a Gmail icon that lives with the rest of the apps on your home screen, and it lets you quickly launch Gmail with just one tap or click.
Follow the steps for Android devices :
•After signing in, In the browser go to Gmail.
•Press MENU button in your device.
•Choose Bookmark Page and select OK.
•Press HOME button in your mobile, then press MENU button.
•Choose Add > Shortcut > Bookmark.
•Find Gmail and select it.
•Then a new Gmail icon appears on your home screen.
Follow the steps for iPhone devices :
•After signing in to Safari, In the browser go to Gmail
•Tap the + at the bottom of the screen.
•Select Add to Home Screen.
•Tap Add to confirm.
•A new Gmail icon appears on your home screen