I had install the apk on the android i copied the adress ... Provided by the app ...after i got to amethyst - relays - add relay- paste the adress from the apk - save.... How do i know that it's ok sorry for the noob question
Discussion
Yes, that's how you do it. How do you know it's safe, well we trust nostr:npub1w4uswmv6lu9yel005l3qgheysmr7tk9uvwluddznju3nuxalevvs2d0jr5 😂 but we can also review the code that he publishes and build it from source.
Nono not if it's safe .... Just if it's working 
In Amethyst tap this button here and select only your Citrine relay. Make a new note. See if it shows up in your feed. 