The best alternatives to Hey Satoshi are Die With Me, Text-A-Gif, and Berkanan. If these 3 options don't work for you, we've listed a few more alternatives below.
Berkanan is a Bluetooth-powered group messaging app. It gives people a way to communicate in situations with poor or no cellular connectivity. Alongside group messaging, Berkanan also allows private one-to-one encrypted messaging. The range for these messages is about 70 meters, but if there are people between you and your intended recipient with the app installed, Berkanan can send messages further by going through other users' devices.
Web-based gaming platform where every digital interaction within the games is charged/rewarded to make the gaming experience more sophisticated and interactive using micro-economic incentives.