Okay, i gave it a good try, using Anvil as my MIDI import/export application...
I've never used a web-based app before so this was brand new to me, and i wasn't sure what it would do. From your description i thought it would prepare a MIDI track for importation by MPT, but not so -- i hafta do all the work!
Once i figured where to find the info the little program needed, i followed its instructions and altered the MIDI, saved it*, and then imported it into MPT, which, for those who don't know, will transmogrify the MIDI data (not the MIDI file itself, so that's safe) into an IT-compat track. *Word to the wise: once you make your changes suggested by this MIDI Helper to the MIDI file you want to bring over to MPT, be sure to save it as another file, as you will often hafta change the tempo setting for import, meaning the MIDI file will have a new tempo.
I tried a couple of my own MIDI files assembled on a Mac with Master Tracks Pro-4, as well as third party .mid files that came from various sources. The tracks composed on Pro-4 did not retain MIDI instruments (or else Anvil couldn't read them), so i often had to fix that.
But anywho, following the instructions DID lead to a better import into MPT. There should be clearer instructions as to the "Row units" as in, "Which note length should one row in MPT represent? Enter its Units amount." or some such. But i did figure it out eventually (i'll be the first to admit i overthink things) and when i followed the instructions it seemed to always work. It is after all only a helper, and what it's helping you do is modify the tempo of the original track, then fixing MPT's MIDI Import options so it'll delineate it properly into your patterns.
So all in all, it does what it's supposed to do, and makes MIDI import 100 times easier, as it does all the calculations for you. But it is a bit clunky and with this wonderful technology, it should somehow be incorporated into MPT's GUI.
Excellent work, Bavi!
We thank you!!