ViralSweep - Grow your fans and increase sales with sweepstakes and giveaways.
Proofy - Quickly validate and verify your email lists.
Retweet Pick - Retweet Pick is a random name generator for Twitter giveaways via generating a winning name from the list.
Trumail - Free email verification API
Retweet Picker - Retweet Picker is an online tool that is helping you to select the random winner from Twitter for the giveaways.
Email List Verify - The Fastest Way to Improve Email List Deliverability and ROI