I don't know if they penalize it but they recommend against it:

    App download interstitials

    Many webmasters promote their site's apps to their web  
    visitors. There are many implementations to do this, 
    some of which may cause indexing issues of smartphone-
    optimized content and others that may be too disruptive 
    to the visitor's usage of the site.

https://developers.google.com/webmasters/smartphone-sites/co...