How to customize product price in products page using shopify app?

[SergejMelihov]

Hello.

I'm new on shopify app development and want to develop simple shopify app that shows the price included tax like as this image.

I tried to find the way how to build the shopify app, so I find the way building the app, but this helps me to create the app working on the store admin panel.
How can I add this price element in every store product page?
If you know how to do this, please help me.
Thanks.
Regards.