As far as my knowledge goes it depends on what you mean. If you mean embedding a web app in a web view of a mobile app then the answer is definitely no. Both stores have strict rules against this.
If you mean though the trend I also noticed, big software companies tend more and more all the time to transfer software to the web in order for it to be able to run from everywhere. It is the lazy cross platform app. Personally I can understand the "build once, run from everywhere" intention but I do not like it. Of course most big software companies have not discovered yet B4X.
The difference between a web app and a mobile app is that the second is full of native controls of the platform, that you use to fire events and execute code in the local processor. A web app is full of web controls common for all platforms that fire events executing code on server's processor (although it can execute javascript locally - client side) and you just display the results of this code execution in a platform's browser.
