You have been asking for it, and we have developed it! The import-export feature is now out in the latest version ( >v1.5.4 ) of Appsmith. With this, you can easily migrate apps from your self-hosted environment to Appsmith cloud or vice-versa.
Read the full announcement here: Announcing the Import-Export Feature for Appsmith Applications
We appreciate each contribution and piece of feedback that you share; keep them coming. Kudos to @Abhvsn and everyone who had worked hard on getting this feature out.