Rather unexpectedly I have managed to generate a few hundred dollars in the past few weeks from a few apps on the store. This is a bit of a surprise. I'm definitely keen to keep improving them and have done the home UI for another app I think will do alright too.
I will continue to follow this strategy of diversification in terms of throwing apps at the store in an MVP style state and seeing if they get any traction, then rapidly improving them once I have proved they can get a ~10+ downloads a day.
So far one has "failed" (at least in its current state), one has started to generate revenue and one has potential (getting downloads/a few trials etc). The last one is the one I am most interested in developing and think it will do the best in the long term but it will be interesting to see whether I am correct here. I suspect I will be in certain ways but maybe not how I would expect.
Once I have done this with 5-10 apps I will slow down and start to concentrate on the 2 or 3 that are performing the best. This means focussing on localization and other app store which can bring in some "free" downloads a day without much more effort.