i downloaded the wallet with Chrome. The problem is that the client does not load fully. The BTCD wallet icon shortly appears in the dock and then closes automatically. For that reason, there have not been created any system files.
Here is the crash report.
Process: launchd [13776]
Path: /Applications/BitcoinDark-Qt.app/Contents/MacOS/BitcoinDark-Qt
Identifier: com.yourcompany.BitcoinDark-Qt
Version:

(

)
Code Type: X86-64 (Native)
Parent Process: launchd [117]
Date/Time: 2015-06-17 21:54:14.538 +0200
OS Version: Mac OS X 10.7.5 (11G63)
Report Version: 9
Crashed Thread: Unknown
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00007fff5fc01028
Backtrace not available
Unknown thread crashed with X86 Thread State (64-bit):
rax: 0x0000000000000055 rbx: 0x0000000000000000 rcx: 0x0000000000000000 rdx: 0x0000000000000000
rdi: 0x0000000000000000 rsi: 0x0000000000000000 rbp: 0x0000000000000000 rsp: 0x0000000000000000
r8: 0x0000000000000000 r9: 0x0000000000000000 r10: 0x0000000000000000 r11: 0x0000000000000000
r12: 0x0000000000000000 r13: 0x0000000000000000 r14: 0x0000000000000000 r15: 0x0000000000000000
rip: 0x00007fff5fc01028 rfl: 0x0000000000010203 cr2: 0x00007fff5fc01028
Logical CPU: 0
Binary images description not available
External Modification Summary:
Calls made by other processes targeting this process:
task_for_pid: 1
thread_create: 0
thread_set_state: 0
Calls made by this process:
task_for_pid: 0
thread_create: 0
thread_set_state: 0
Calls made by all processes on this machine:
task_for_pid: 12332
thread_create: 0
thread_set_state: 0