The CouchDB module provides API access to any Couch Database. The API exposes a majority of the Database, Document, Design and Views API. The CouchDB module when enabled does not do anything.
The sole purpose of the Alter Profile Page module is to bring more of social networking, MySpace-ish look to Drupal's user profile page.
Enabling the module will change what appears on the users' profile page(s). By default, the Drupal core sets the profile page to display a section called History, under which you'll see Member for which then displays XX weeks YY days. Please see the attached screenshot for a before and after look at what the module does.