As of version 1.9.x of the app, Approval documents for Correspondence is supported.
Any document sent for your approval* will appear in your Hotlist on iTWOcx Mobile
You can respond to these documents.
For more details on how to manage Approval documents click here.
Status
The is also an option for a quick approval with a side swipe on the document row
*Approvals are limited to Correspondence documents ONLY.