Syncing between Imac, Macbook, Android phone and iPad

[theRandomizer]

You could check out this post which shows multiple approaches with instructions to sync between devices using 3rd party services

Meta Post - Syncing between Devices

The official documentation for syncing Obsidian across devices is a great place to start. If you have ideas to improve the Obsidian documentation, pull requests are welcome. You can contribute to the process of documenting Obsidian on GitHub. First things first: Obsidian Sync vs. Third Party Sync. The advantages of Obsidian Sync is that it’s officially supported, “just works,” has nice versioning that is built into Obsidian, and is blazing fast and optimized for your vault. The main tradeoff is…

I personally use Syncthing which is an amazing free and open source service with a lot of advanced options