Question:
I missed attending a siyum this morning. Is there such a thing to download and listen to shiurim of a mecechta (perhaps whichever is the shortest one) and then on completion, THAT is my siyum and I can go and grab something to eat/drink?
Answer:
If you can learn an entire maseches, by any way that you can (the shortest is Tamid), then you will be able to make a siyum upon completion and eat.
Good luck and Chag Kasher Ve-Same’ach.