Tried of deleting your emails one by one? Read this Android tip to learn How to Delete Multiple Emalis on Gmail Android App. First update to New Gamil App and then do as follows
1. Open "Gmail" App for Android
2. Tap an email you want to delete (Note that you MUST tap the image left to the screen)
3. Now tap other emails to delete (see the counter on the top left, which shows home many Emails you have already selected)
** If you don't see this icon, tap the three dot icon on the top right, and select "Delete"