Globally the craze is about mobile apps. I always consider the business part of development before I begin. Java is the most popular in Nigeria no doubt (considering that Nokia and Blackberry both support java). I did some Java apps which are doing better than I expected in the Nigerian market. Check them at http://www.greenspek.com.. These apps are tailor specifically to the Nigerian market cos I honestly don't see them selling outside Nigeria.

However, I have some app ideas (with global appeal) which I want to sell in Nigeria and other countries and I don't think Java will do the magic.
I'm looking for a platform that will cut across both markets (local and foreign).

I think the key question is: Which phones are more popular in Nigeria, iphones or andriod phones?

Both are expensive and hence unpopular.

Iphone is more expensive though and, knowing Apple, will probably always remain so.

If you want your applications to be bought in this country develop a Java or BB app.