Why is Piktures not open-source?
The code is all we have.
Many concepts in Piktures are unique to it. The source code is our intellectual property, and it is where the value of our work is stored. There's no Piktures account and no social network behind the app: we just have a fantastic app.
Making Piktures open-source would let other developers take our work. We have come to believe that the Google Play Store is filled with gallery apps that copied Google's original gallery app. We are not sure and cannot prove it, but it is quite striking that they all look the same, and that many of them are mostly there to show ads.
Piktures shows a few ads too, in its free plan, and any paid plan removes them. This is how we fund the app: see How do we make money.
We have created something unique, and we care deeply about it.