AddThis - AddThis free website tools include share buttons, targeting tools and content recommendations help you get more likes, shares and followers and keep them coming back.
ViralSweep - Grow your fans and increase sales with sweepstakes and giveaways.
Sharingbuttons.io - Quickly generate social sharing buttons with a tiny performance footprint.
Retweet Pick - Retweet Pick is a random name generator for Twitter giveaways via generating a winning name from the list.
AddToAny - Share buttons by AddToAny, the universal sharing platform for websites and apps.
Retweet Picker - Retweet Picker is an online tool that is helping you to select the random winner from Twitter for the giveaways.