Ballwool - social network marketplace
LoveSales - Find and save products you love, get alerted when they go on sale.
21 Buttons - Like to be on top of the latest trends in fashion?
TrackIf - Alerts you if the price of your favorite products drop
LIKEtoKNOW.it - Shop your favorite Instagram accounts
Giftwhale - Giftwhale allows you to create personalised wish lists online.