nostr:nevent1qqsyevrsllqahu3rphfg4t7lm2qt2r8vgpuvyg7qzgmslqqczuj50pqpz9mhxue69uhkummnw3ezuamfdejj7q3q8ams6ewn5aj2n3wt2qawzglx9mr4nzksxhvrdc4gzrecw7n5tvjqxpqqqqqqzvmdqv6 

 It’s literally a relay on your phone. It backups events you post or others depending on how you set it up.
You can also use it on Amethyst as your private relay. 
 I didn’t know about the offline posting feature Derek described.