cell9 the developer behind NTR CFW 2.0, has released NTR Debugger 2 along with its source code, here is a quote from the source:
The NTR Debugger 2 is the first public debugger on N3DS, which is very useful for developing plugins or homebrews. Here are some of the features:Debugging on wifi
: connect your N3DS to local network, and enjoy debugging on computers.Breakpoints
(code breakpoints and one-shot code breakpoints): which is a typical feature for regular debuggers.Memory viewing/editing
: list processes, view thread list and stacks, and attach to process.