1. Some functions need to work with the sim card, some functions need to work with the memory card which is not included in the watch and a few functions need to work with the BT Notification app. You can scan the QR code to download the BT notification app or download other BT Notification app which is compatible with Q18S to your cellular phone.
2. A sim card is needed to be inserted into Q18S if you wish to connect Q18S to internet; Internet link speed is very slow because of Q18S supports 2G network only,so it is not a good selection if you wish to use Q18S to surfer internet;"Whatsapp, Facebook, Twitter, Browser" almost can't be opened because of the very slow link speed to internet, so it is not a sensible choice if you wish to use those apps on the watch.
3. Whatsapp, Twitter, Facebook are useless apps because of the watch supports 2G network only, they could be deleted from the watch without prior notice in order to optimize the watch's system.