Perfect Forward Secrecy - Really well done!
I've just read an article about SSL browser encryption. It said that Perfect Forward Secrecy (http://en.wikipedia.org/wiki/Perfect_forward_secrecy) is a very important property but even the big players like Microsoft, Amazon etc. don't use it.
So I looked at Todoist and I am surprised - you use it! That's again another prove that Todoist is a really great product also regarding security! :-) Todoist's little team does a better job than global IT companies with thousands of employees! :-) Really well done!