$4m = VoIP phone number, call-in, call-out features: what this means is that we need to reach the $4 million milestone to hire the Matrix team to implement calls to/from the POTS/PSTN, to complement the existing VoIP features. $6m = Reverse engineering faster WiFi/Bluetooth firmware $8m = Free encrypted VPN tunnel service for all backers for 1 year $10m = Run Android applications in isolation on the Librem 5