You’re welcome! Glad I could help.

I think Neoformat lets you format a buffer without saving it, without the need for an LSP. So you could:

:enew 
:set syntax=json
(Write some code)
:Neoformat <formatter-name>

https://github.com/sbdchd/neoformat

The link won’t load for me (on iOS), it says no secure connection could be established.

For iOS there’s Mlem, which seems pretty alright—using it right now. Not sure about Android, or if there are any other iOS options.