I am interested in developing games for the Android OS. I have played Replica Island and I have browsed over the source. I found that the levels/maps were in a .bin format. I could execute them because they were in an Android format. So how could I make a game map/level that could be used in my game? What program would I use? How could I load the map in Java (for Android)?
I think you're missing it a bit here. What happens is that your game or app is run, and that then opens and reads in the data from a map file. The map file is not actually executable, it simply holds data.
Say you have a tile map of 10x10 in a 2d array. Say that it is all water (tile ID 0) and grass (tile ID 1). You would save this into a file, row by row, probably in a binary (not human readable) format. So if your map had a few rows like this:
(It's repeating, but it's an example. All the 0s are water and 1s are land)
You would go through each row and save it to a file. So your file would just be, in binary:
When you come to read it in, you would read in number by number, and you know that a 0 is water (and you would set that tile to be water) and the 1 to be land.
Of course, this is very simple. But the chance is you would have an ID system, so rather than saving 'water water land' you can do '001'. Same for items - instead of 'sword, location 1,0; axe, location 3,0' you would maybe write yours in binary as '45 1 0 76 3 0'.
For Java, look up any kind of file API documentation.
Usually, you make a map like lets say a 2D array, and then output it in whatever format. Binary is small and fast, so you might want to use that. You would then have a reader in your game which would parse through that file (binary or whatever) and load your "level" data structure accordingly.