If it has a developer defined UID it will be in the manifest, saying that I've looked in Opera Mini and it doesn't seem to have one.
MIDlet-Name: Opera Mini
MIDlet-1: Opera Mini, /i.png, Browser
MicroEdition-Configuration: CLDC-1.0
MIDlet-Icon: /i.png
MIDlet-Info-URL: http://mini.opera.com/
MIDlet-Permissions-Opt: javax.microedition.io.Connector.sms, javax.wir
eless.messaging.sms.send, javax.microedition.io.Connector.socket, jav
ax.microedition.io.Connector.file.write, javax.microedition.io.Connec
tor.file.read, javax.microedition.pim.ContactList.read
MIDlet-Vendor: Opera Software ASA
MIDlet-Permissions: javax.microedition.io.Connector.http
MIDlet-Version: 8.0
MicroEdition-Profile: MIDP-2.0
MIDlet-Description: Opera Mini
Nokia-MIDlet-No-Exit: true
Nokia-MIDlet-On-Screen-Keypad: no