SharePoint Hosted APP - Timer Job ?

The clear cut answer is No. You can't add timer jobs in SharePoint Hosted Addins.

 

If you try to add timer job in SharePoint Hosted Add-in, then in that case a new c# solution will be added to your add-in and your add-in will automatically get converted into Provider Hosted Add-in because now you need to host timer job to somewhere outside the SharePoint.

 

So it is better to create SharePoint Provider Hosted Add-In.

 

you can refer the detail answer here https://sharepoint.stackexchange.com/a/239456

 

I have already created Remote Timer Job In SharePoint Provider Add-in.