Month ago, I finally got a MOTO Milestone2 and frankly Android is so fantastic!
I also try Ren'Py on my Android, using the default tutorial. In truth, there are some AVG and ren'ai games on Android which were developed by NScripter and now could run well on Android by using an emulator called ONS. Sorry, I do not know how to call it in English...and either do I have an English website to show it...
Clearly, ONS emulator must using a specified kind of game resources, there are still a lot of bugs.
To my surprise, ONS runs very smoothly on my Milestone. Loading the game is just a bit of while, and menu buttons react very swiftly as soon as I press them. Kinds of transitions have become reality such as fade-in and fade-out. But some elements have lost such as text box of each character and option settings.
Ren'Py is pretty good, and the image on my phone is much more in detail. However, I want to know, if it is the image of the tutorial too big for my Android phone, that makes it reacts a bit slower. And I am eager to see more support of transitions in Ren'Py (I know PyTom is busy working on it!).
Moreover, can Ren'Py do some more on Android? I am to say... such as in-game menus, when there is a scrolling-bar beside it, it seems impossible to select the item which is not shown on the screen... Say, I must try to scroll down the srolling-bar... I just want to have the same function on Android when I'm scrolling the screens...
(Sorry for my English... And thanks for listening!
