Sad Migration

I've been an ardent promoter of Omnifocus for iOS for several years.  That software changed my life by organizing my personal projects.  The iPad version of Omnifocus is in my short list of most useful pieces of software ever.  If you use iOS, I highly recommend it.

Unfortunately, I'm no longer in the ranks of iOS users.  I'll go into the details why I'm walking away from Apple in a post for another day.  So I'm looking for a replacement for Omnifocus that will run as a Webapp and/or  Android application.

I believe that if the folks behind Omnifocus would port their masterwork to platforms other than iOS/OSX they'd own the market.  Sadly, they don't seem to have the slightest interest in doing so ( Omnifocus for Android is very unlikely ) and so I must walk away from Omnifocus.

So what is the replacement for Omnifocus?  There just doesn't seem to be one.  I've looked into several options like "Remember the Milk" and "Astrid", but they just don't measure up.  I rely on the project management features that just seem to be missing from these alternative projects.

Do you use personal project management / GTD software on Android / Linux and/or as a WebApp?  Can you recommend it?