Three month project is over and I can share the result. I built all missing components to make it able to develop iOS projects using Windows and Linux host.
First of all what it can’t:

2017 was quite effective for RoboVM as for me and there was lot of things introduced in it. I’m pleasured to contribute bunch of shiny things as well. But things change and in all RoboVM projects I was enrolled are winding down in 2018. This changes few moments for me:

History Debugger hangs due exception on ARM64 target when trying to resolve stack variables #239
Fix PR #240

Have almost never debugged ARM64 target (always used thumb7 as faster and smaller), but turned out that debugger is pretty broken. The reason is forgotten case:

History NPE not handled when Robovm used as SDK

Few finding when working with RoboVM built framework from XCode. Today there are two examples listed of how to build framework with RoboVM:

History IB integrator generates wrong class name for empty @CustomClass, doesn’t support structs in IBInspectable
Fix PR231

Have discovered that User define attributes/UIInspectable are not handled correctly: XCode project is not generated, if just added in code bypassing IB – values are not set in case of field outlets. Structs that causes problem:

History RoboVM doesn’t strips all simulator archs from dynamic framework which causes ITMS-90087 during submission #228
Fix PR229

This kind of problem always was bothering me but I was under impression that stripping is not part of RoboVM and did this all time manually before submit. But it is there but broken due epic bug:

github user @obigu reported that he observes crashes in 0.1% of sessions related to code in icu. it is well known dances around icu.dat but it should not cause crashes. First of all it was required to obtain Locale id example that caused crash.
UPDATE: also included rfc3491 to fix #86

UPDATE: Commercial RoboVM has nice tutorial about IB (still available today). OOS RoboVM implementation has own differences and these are covered in this post. It is not possible to use Java classes with Interface Builder directly. To workaround this dummy objective-c XCode project is generated. This project contains:
UPDATE2: web archive

In RoboVM’s cocoatouch there are bunch of NSError subclasses that don’t exist in objc iOS itself. For example WKError This is hand written class required to allow RoboVM’s NSError return object error code which can be used to compare against enum members, such as WKErrorCode.
NSError provides information by following properties:

UPDATE: another workarounds explained in new post
A try to use BC within idea plugging ends with following:

Caused by: java.lang.SecurityException: JCE cannot authenticate the provider BC
	at javax.crypto.Cipher.getInstance(Cipher.java:657)
	at javax.crypto.Cipher.getInstance(Cipher.java:596)
	at org.bouncycastle.jcajce.util.NamedJcaJceHelper.createCipher(Unknown Source)
	... 97 more
Caused by: java.util.jar.JarException: Class is on the bootclasspath
	at javax.crypto.JarVerifier.verify(JarVerifier.java:247)
	at javax.crypto.JceSecurity.verifyProviderJar(JceSecurity.java:160)
	at javax.crypto.JceSecurity.getVerificationResult(JceSecurity.java:186)
	at javax.crypto.Cipher.getInstance(Cipher.java:653)
	... 99 more

This was happening with RoboVM idea plugin but in general issue is wider. First thing attempt to fix it includes: