I purchased software dec. 2015 now it's asking me to buy it again why?

If you purchased through the app store, just login to there and that should solve the problem.

Hi Josh B.,

can you send us a mail via support@algoriddim.com and tell us where you purchased djay, which djay you are using and which mail you used to purchase djay.

Thank you very much.

Cheers,
Lukas E.