Is app installing possible?

At this point in time, Linode does have a serverless product for deploying your app. For now, you'll need to deploy a compute instance to host your application. If your app is running on Node.js or Django, you can cut out a step by deploying an instance with those services installed already from the Marketplace.

In the meantime, I've added your request for a serverless solution to internal tracking for features. Be sure to keep an eye on our blog for updates on new products and join Linode Greenlight to be included in any upcoming betas.