Using android JAVA with ionic

I have an Ionic app. for both iOS and android.
there are a number of simple html pages and two “special” pages: a google maps page and a page with a canvas game.
while the html pags work fine in both platforms.
the canvas game is noticeable slower on android and the google map crushes after some time on samsung s4 (nexus4, s2 & s3 are fine), the map starts to have black tile instead of the map’s tiles…

do any one have suggestions what is wrong and how to fix it?
alternatively, is it possible for to make the app open an android native activity instead of the buggy html pages. where I’ll have native performance for my heavy duty parts of the app?

thank.

is it possible for to make the app open an android native activity

It is possible to create a native project that includes a Cordova WebView along with native views.

That’s a pretty different approach to creating an Ionic/Cordova project that only uses native functionality via Cordova plugins though.