IceWeasel is the GNU version of the Firefox browser. Unluckily some web services, like the Google extensions installation, doesn't recognize it as a Firefox compatible browser. A quick workaround is to go directly to the Firefox link:
Good FTP client:
It is possible to interface to the VoipStunt service through Ekiga (H.323 & SIP):
Ekiga package
apt-get install ekiga
Ekiga settings
Edit -> Preference -> Protocols:
Network setting:
NAT traversal Method: None
STUN Server : stun.softjoys.com:3478
Sip Settings:
Outbound Proxy: sip.voipstunt.com:5060
Forward url : sip.voipstunt.com
Send DTMF as : RFC2833
VoipStunt account
Edit -> Accounts -> Add:
Account name : voipstunt
Registrar : sip.voipstunt.com
User : *********
Password : *********
Authentication Login: ********** <--- (User)
Realm/Domain : voipstunt.com
Registration Timeout: 3600
sip:+39**************@sip.voipstunt.com:5060