something like a simulator in corona
MOAI has basic desktop builds you can use for testing. Look in the `bin` directory in the SDK distro. The samples folder contains scripts (.sh and .bat) for running the samples in the desktop client.
How does an optimized workflow look like?
Lots of options.
Akuma (I believe that's the name) is a client on Windows that automatically reloads your app any time it detects a change in your application's directory, which means you never leave the editor; every time you save your app reloads.
If you jailbreak your phone, you can install OpenSSH which gives you wireless access your phone's file system and lets you send it commands. Using something like ExpandDrive, you can then map the device's disk into your phone's file system. This makes testing directly on the device very easy.
You can use your desktop editor to edit scripts directly on the device and map a key to restart your app.
You can even edit scripts directly on the device (I do this on my iPad sometimes), if you have a suitable iOS editor installed (I use console Vim + iOS SSH client connected to localhost + bluetooth keyboard).