I want to add to my last answer.
For some reason, yesterday my phone showed a download icon in the internet address bar next to the URL and I clicked on it and it downloaded the app to my app drawer.
It wasn't there before, some other forums I belong to have the same download button next to the URL but grow diaries never did until yesterday.
The icon I'm talking about in the address bar is just a square with an arrow pointing down.
This works better then my previous answer of "add to home screen" since you can put the app anywhere, not just the home screen.