Zaxby’s loyalty rewards program has driven record engagement for the brand. Zax Rewardz, the recently relaunched mobile app, has outperformed the industry year to date. The loyalty program features a free Big Zax Snak with each new download through the end of the year. Zax Rewards is America's fastest growing restaurant app, based on growth of user sessions as reported by Apptopia. The restaurant chain is celebrating this digital milestone with a special offer: customers get free delivery with orders of $35 or....