Our app does not have shortcuts you can use, but we have listed below, some of our favorite Gmail Keyboard Shortcuts: 

To select a continuous series of emails (Shift) -

Check the box for an email, hold Shift, then select the last email in the series.

Select a random series of messages (Command) - 

Check the box for an email, hold Command, then choose the designated emails.

Select all unread messages (Shift + 8 + u)

Hold Shift and 8, then press u to select all unread messages. Use this in combination with the next shortcut (archive) to quickly archive messages you don't need open. 

Archive selected messages (e)

After the boxes are selected for the messages - to archive (using one of the above three methods), click e to archive them. 

Mark selected messages as important (=)

On the contrary, when you have numerous important messages selected, press = to mark them all as important.

Compose (c)

Sometimes to quickly compose a message from the inbox view, press c to do this. 

Search for messages (/)

When you need to search your inbox, press / to quickly put your cursor in the search tab.