Retweet Picker - Retweet Picker is an online tool that is helping you to select the random winner from Twitter for the giveaways.
Proofy - Quickly validate and verify your email lists.
Twesocial - Twesocial helps you grow your twitter with real twitter followers. Real results, real people.
Trumail - Free email verification API
Tweeteev - Get more Twitter followers with the best twitter growth service on the market. Tweeteev will effortlessly grow your twitter profile with real, active followers.
Email List Verify - The Fastest Way to Improve Email List Deliverability and ROI