DKD 1.2 is out! Unfortunately, there are reports coming in of the app crashing during the data upgrade step. I'm still working on figuring out the cause.
If you don't have any saved data (lists or custom cards) that you care about, then the fastest way to get past this problem is to delete the app and reinstall it from the app store. This will clear all of your existing data.
If you have a lot of data saved up, then contact me at email@example.com and I'll work on figuring out the problem and getting you an adhoc version to get past the problem.