When comparing Codename One vs NativeScript, the Slant community recommends Codename One for most people. In the question“What are the best frameworks for developing cross-platform mobile apps?” Codename One is ranked 7th while NativeScript is ranked 9th.
Ranked in these QuestionsQuestion Ranking
Pro High performance
Pro Open source
Pro Highly customizable
By utilizing lightweight component architecture and the built in graphical designer and theming options you are able to customize a good looking app on any platform.
Pro Java 8 support
Pro Works with all IDEs
Works with NetBeans, Eclipse, IntelliJ, etc.
Pro Multi-platform development environments (via build server)
You can even use Linux desktops to build native iOS apps, no need for a Mac.
Pro Vibrant & helpful community
Pro Attractive pricing
It is possible to build production grade apps even with the free version. Pricing is decent when compared to competitors like Xamarin.
Pro Svelte Native
Used by Svelte framework for native development.
Pro Leverages knowledge in Angular
Angular is a very popular framework, and teams already developing angular will feel right at home with Nativescript + Angular
Pro Works great with vue.js
Con Nativescript + Angular apps for Android tend to have long startup times.
It's very difficult to have acceptable startup times with NS+Angular in Android. It's not uncommon to see apps taking 6 sec or more to start AFTER having been optimized with Webpack (mandatory!). The same app in iOS takes only 2-3 sec. Also, this seems to happen only with the NS+Angular flavour. People using plain NS (without Angular) don't seem to have the issue.