The application is actually just revamped as I understand it (based on the above review by Startup North); maybe in a major way but still based on a previous product. As Ted from Kik has responded below, they e-mailed nearly all of their 55K previous users, though very very few of them converted.

Their history deserves mentioning and is likely what put them in a position to be able to launch, market and scale effectively. The users may not be the same, but the strategies and the tactics used to get there are likely based on previous experiences as well as having some great people get them this far.

Obviously this community isn't the target of their post, but I would be even more interested in hearing the whole story: how they went from zero to 55K customers in 7 months, lost almost all of them, and then scaled it back up to a million users in two weeks