Both the blogs claim that twply was sold off for $1200 and along with it all the user credentials have been transferred to the buyer.
What this means is that your twitter account could be misused by the buyer!
You need not panic. I guess there is a way out of this mess.
The easiest thing to do would be to change your twitter password. But that would mean having to change the password in all the other twitter apps that you regularly use.
So, I suggest you follow the steps below :
What would happen is that twply would now have your new password whereas you would have reverted back to your old one.
P.S. The most fool proof way still is to change your password altogether. I have suggested this method because I know of a lot of friends who use the same password for all their accounts. In such cases following the above steps would help you in avoiding a lot of trouble.