If you need a plan b I might be able to help. I've been a programmer professional for the last 16 years. (front end and backend web apps) If your interested I can provide more details of my background/experience and my startups.
One thing you might try to do is set a deadline by setting up an important meeting to show someone the prototype. That way there is more of an urgent need to get point A up and running. If he can't get it finished a few days before the meeting then you have your answer on what you should do.
That is what we are using for my startup http://www.linkies.com. (#Linkies) is a bookmarking service for posts or web pages organized by hashtags. We use something very close to that to group hashtags together. We call them (#grashtags)
Also one last thought. Always have in writing what happens when someone is leaving or is getting kicked out. could be a buyout. Or a percent of buyout. bottom line is I think you should get with your other founders and formulate a plan and then get a lawyer to draft up new company bylines ASAP.
You should have planned for something like this to happen from the very start. you should always have a "divorce" agreement in place in case someone isn't pulling their weight, stops working on the project, medical leave, etc. I know this from learning the hard way. You should also aways have a vesting period in your contract. 2-4 years should be given to startup before they get 100% of their shares. Not where you stand now nor am I a lawyer but you might want to get that agreement in place. Maybe tell him that you need to slightly redo corp paperwork to bring in other people/investors in the future. Good luck.
I just got done filling for my first patent. It's a great feeling (when your finally done) and I wish you the best of luck. My patent lawyer told me to use http://scholar.google.com/ she said its what the patent office is now using to search for prior art.
You should check out linkies.com - disclaimer I'm a co-founder. Anyways linkies organizes your posts/bookmarks based on the hashtags you use. You can even group hashtags into groups that we are calling grashtags. You can also subscribe to just the topics you are interested in to create a custom news feed of links updated by the people you trust. it's currently in private beta but let me know if you want early access and I will see what I can do.
That is why We built linkies.com. Currently in private beta. It organizes your links/posts based on the hashtags you use while posting. You can also make groups of hashtags into what we call grashtags. You can also subscribe to other peoples posts based on you interest to create a custom news feed of things you care about. Let me know if you want early access. I'll hook you up.