I just skimmed Anki & mnemosyne as well as MemStash. Early constructive criticism: I think all of these tools would benefit from a web-based demo that doesn't require a download & install or a signup / login.
As an example, I watched the Anki intro video http://youtu.be/c0dI2VyLDWw and I found myself wanting to try my hand at state capitals immediately, but not enough to download and install the software.
Building a quick web playground that lets the user try quick quizzes may capture people and hook them in -- at least it would for me.
As a long time SRS user, I couldn't understand the flow of the US capitals example at all. Using Chrome/Linux, I only had one answer to begin with, and that was really confusing. The gradual multiple choice didn't make much sense for me, and it won't make much sense for language. With language, I just want to click on it and see if I was correct with my verbal guess.
I don't like the waiting for ten seconds for a new flashcard at all. Why am I staring at your screen for ten seconds? or a minute! I'm just going to leave and not return.
I personally have no interest in SMS, but others may. What I care about is push notifications and mobile software. (I paid the $$$ for anki, but it doesn't have a way to remind me to go through my cards daily.
Honestly, I think for this kind of startup, you'd be well served to read more of the research of learning, because what I see doesn't match up with what I've personally learned on my journey.
You're right, the one card at the beginning is confusing; I plan on showing more at the onset to counter that.
I was hoping users would click the "show more cards" button when they got to the waiting screen, not actually wait 10 seconds. I should probably add some help text to encourage clicking this button.
The reason I'm experimenting with multiple choice over just asking "Did you get it right or wrong" is to make for a more casual learning experience. After a few days a card turns into typed answer so the user can prove to themselves that they still know it. I am considering adding a traditional flip and self score mode to accommodate users who want that.
My plan is to make a native app with Notifications; the SMS thing is just a temporary way to get the deck onto the phone since there's no login system yet.
If you have time, I'd love to pick your brain as to how you learn. If you do, shoot me an email: firstname.lastname@example.org . Thanks again!