Some history:
We have spent a large portion of our daily company time developing something like Apportable for apps, not games. We tried Apportable on multiple occasions and it's too game focused. Our clients all want Android apps but basically don't want to pay for them or spend time on them, for them, iOS is the first class citizen, Android comes far behind that and the rest is usually not even mentioned. Especially line of business apps are very much like: make the iOS perfect and 'the rest' (as much as you can do fast/cheap) should be done, but don't bother us with it.
Status:
We compile the iOS apps we build to Android and release them; we currently also have alpha versions for WP8 & HTML5 which work well enough. But we need to do it (just like Apportable by the way) currently; we 'fix' our library when there are methods / classes missing. We allow, in quite intuitive ways, to use the native API's where clients want/need to.
Future:
We would like to finish this so it can be sold online, maybe as a service or download; currently it's sold together with every project we build and that works well but the money from that is not enough to 'finish' this into a product. To finish that entire phase and start selling worldwide (instead of project based, which, by the way, is still a lot cheaper than doing an Android implementation yourself) we need more money then we can fund ourselves. We are situated in Europe and the investors (mostly angels) we speak to either have no clue what this is or how much upside it has or offer far too small amounts for too much % (usually actually less money than we can make ourselves selling it in a month or two which is just not enough to invest in it).
What would be a good route for us to finding the right people? It does not have to be in the EU/UK, but that seems the most likely option.
You're solving a real problem for a real market. You will help thousands of app-developers reach a wider audience with a better product. You're selling shovels to golddiggers, you're not digging gold - that's a good business proposition. Do some back of the envelope math to figure out what the market is worth, and come back with the question "How do we find an investor for a great business?"