Your thoughts are safe in Amethyst Drafts! 
nostr:nevent1qqsr2wmhqsft8mrn5h5jgwua07x2flxrf2xry2kqggutna54que0mcqpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsygzxpsj7dqha57pjk5k37gkn6g4nzakewtmqmnwryyhd3jfwlpgxtspsgqqqqqqshuw5cn 

 Yes. And it you add a private relay your drafts additionally will only be stored there. For example Citrine, on your phone. 

 What else citrine is good for? 

 You can, if you are a hardcore user expose it to Tor and use it as inbox relay. So people can send Dms to your relay on your phone without ever needing to use any relay. 

And you can backup your notes 

 I was thinking to use citrine along with locus app. What do you thini of this? 

 What's locus app? 

 https://f-droid.org/packages/app.myzel394.locus/