How to manage forwarding email from smartphone? I am not able to find the setting to manage the forwarding option in gmail application.

Where I can manage it from the smartphone with android 4.4.4?
If you want to forward an email open the email, click the three dots in the corner of the message and tap the forward button. If you want to forward all of your emails to another address, there is no option in the app. You can do this via the web with the following instructions: https://support.google.com/mail/answer/10957?hl=en. If you need to set this up over mobile for some reason you can achieve this by selecting the "request desktop site" option.