Use DriveSync app and Google Drive to sync Obsidian desktop to mobile Android.
- Put your vault in Google Drive
- Download DriveSync (aka AutoSync for Google Drive) from Google Autosync for Google Drive - Apps on Google Play
- Set up a synced folder
- Sync method: Two-way
- Check “Select files by name” and configure these inclusion/exclusion patterns: DriveSync Ultimate – Obsidian Inclusion/Exclusion Name Patterns · GitHub