j2me is a technology that was used a couple of years ago to create these applications on cheap phones (I think, before smartphones). Blackberry and Symbian have slightly expanded java libraries, but it still looks like j2me (it hurts to create applications that don't look good plus in later global events. Symbian os is becoming more and more unpopular, which means fewer and fewer developers necessary).
But basically the main part of mobile applications is written in java, one of the ways of the other. There is also iOS that uses xCode. maybe even some built-in development platforms that use C ++ or something, but I canβt say for them.
EDIT:
Oh, and yes, there are now Windows mobile devices that are becoming quite popular. in my opinion, itβs actually a good idea to develop mobile applications on Windows 7. Although it is currently quite poor in terms of available community resources, etc., it may grow in the next year or two. In addition, application contests are quite small, the market does not exist, so it is easier to push through a successful application (which does not apply to iphone, and the Android market is filling up very quickly).
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