Boost app starting with Google maps

Hello everyone!
Is there any features or tips for boosting app start when using google maps javascript api.
My app starts veeery slow it because of loading map.
I couldn’t use http://market.ionic.io/starters/google-maps because my app already builded fully but its lagging and stucks on app starting about 5 - 10 seconds.

If anyone has some solution or tips please to share.
Thank you