What's the best new app you discovered in 2018?

What's the one app which you discovered in 2018 and feel that others should know about it.

Originally posted by Shane Parrish (@farnamstreet) on Twitter.
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StepSetGo - It gives reward as coins for completing steps, you can earn a maximum of 34 coins/day (more by referral - 5 coins/referral) and these coins can be redeemed for stuffs such as Earphones, Discount coupons, Smartwatches, Playstations and Even an iPhone XR. You can refer your friends and follow them to see how much each of them is walking and see your ranking compared to them. There are levels which increase on completing daily target steps. Rewards redeem price start from as less as 39 coins. You can download it Here .
It also tells average steps per day, average coins per day, total steps & total coins earned. I have 617 coins with me right now. You can watch ads to earn more. It uses Google Fit data.