I am currently trying to make a calendar for a hotel booking system. I have started out by just focusing on a creating a single cell that represents a day. I did this with a class that inherits from ui.View. In that cell, I create multiple subviews for indicators in the top right of the cell as well as indicators in the bottom of the cell cell. Then writing methods in the class to manipulate the contents of the various cell/view. Also some animations within the cell also. The goal being that another class would create as many of these objects as required and position them appropriately to form something that looks like a calendar. Long intro to my main point...
Writing this small custom class, it occurs to me, how hard would be for @omz to be able to load a custom class that inherits ui.View into the ui builder, and at minimum render it and provide graphical positioning. One step further could be to offer a property page if the class had decorated properties for example. I am sure it could go further. But even the simplest implementation could lead to some nice controls/widgets being created for Pythonista in my ui.View.
I hope this is useful feedback.

https://www.dropbox.com/sh/7ueokz1zxofj2bs/AAAgeDb-paugPEpbbvEifx9Xa?preview=File+22-06-2015+18+15+06.png
https://www.dropbox.com/sh/7ueokz1zxofj2bs/AAAgeDb-paugPEpbbvEifx9Xa?raw=1