I also had the problem with alpha45 and a Samsung Galaxy S4. After installing crosswalk the problem (blank screen) was solved.
Running the same app via Ionic View does not work, I get a blank screen, also on a Galaxy S5 (I did not try "ionic run android" without crosswalk on the S5). From what I've understood from Ionic View website, it does not use the crosswalk plugin: "...View uses the Cordova inAppBrowser plugin to launch your apps in their own separate WebView", thus that might explain why the app works via "ionic run android" + crosswalk but not via Ionic View.