I use now two iThings with iTM and M8. Only one is jailbroken. Everything works regardless.
I was hoping for 3L too, but the main problem is that it will not be for firmware 2. But some other development is going on as well. That using OSC protocol, so you need to convert OSC to midi (OSCulator). But it works OK too. M8 has OSC module, but for me it is too confusing to set up. Look at the app store for OSCemote and TouchOSC.
mrmr is still alive and kicking
http://poly.share.dj/projects/#mrmr That allow you to create custom layout. So you can copy M8 look.
I have just tried others, but iTM is so easy to use out of box, so I have stuck with it.
BTW iTM has an app PowerKeys that should allow you to map keystrokes in M8 to 16 buttons on iThing. I have not tried it jet though.