Basically it makes the plumbing required for running tasks asynchronously a bit less tedious. On Android running tasks asynchronously is sort of a requirement as you want to prevent to do too much work on the interface thread, as that would degrade the responsiveness of the UI. So yes naturally anything I/O bound or long running would be a potential use case for Kovenant. A demo project can be found here
https://github.com/mplatvoet/kovenant-android-demo .