Well then there are still a few options; 1) it's internal and you can force-feed it to your employees, then it might be ok 2) it's external and you're trying to get a lot of people to work with it outside your company.
In both cases I still think you are better/easier/happier/cheaper off building it once and in case 1) giving your employees tablets/phones with the target OS and in case 2) just waiting till you have enough critical mass to warrant writing a version for the next OS.
Not to mention that, in most cases we have made HTML5 'hybrid' apps, we noticed that it takes more time making it uniform and smooth across the plethora of (especially Android) devices than just writing 2 native versions. And the HTML5 version will just never work well on a large amount of 'Alibaba $50' Android devices which surprisingly many people have. Resulting in TONS of bad reviews (if public) and/or very frustrated people.
