Any idea of an editor/IDE which highlights code’s syntax for inline templates which are insert in the page with something like the following?
<script id="templates/home.html" type="text/ng-template">
</script>
I am using brakets and it does highlight the code inside script tags. I even opened an issue on Bracket’s github https://github.com/adobe/brackets/issues/10166
You should take a look at intellij idea
Just look a bit further then “java” as they market it best, because intellij has plugins for almost every language I can think of… Also, you could write your own plugins if needed. It handles ionic seamlessly in my opnion. Please use the 30 day trial if you want… The functionality is worth the money, but it depends on how much work you’ll be doing if you’re willing to pay it 
In my opinion intellij is best suited for development in all languages I’ve worked so far, and it highlights multiple language in one file (for example, a php file that prints a javascript script and the javascript that prints some html, will highlight all 3 languages correctly 
)
479 euros is kind of expensive 
How that compares with WebStorm and is there any free alternative?
Webstorm is a lightweight version of intellij with just support for “static web” lanuages. If you check phpstorm, you have the lightweight version for “static web” languages complemented with php features But since you’re creating android/ios apps, it would be recommandable to have your IDE be able to deal with the native languages as well (if you’d ever want to write a custom cordova plugin for example).
I know it’s quiet expensive… Never seen a better one though And I’m not that rich myself either