To group documents in FineReader PDF for Mobile using tags, do the following:

1. Select the document;
2. Tap "..." > Properties;
3. Choose necessary tags from the list or add new tag;
4. Press Done/Save and go back to the list of documents.

To give a unique name and tags to each new document, do the following:

1. Press Menu > Settings;
2. Enable:  
   • Edit before saving (iOS)
   • Show document properties (Android)