In the Android SDK emulator, I see that the such one trivial application has about 53.09 MB ?
Is there a way to reduce the size of applications to a reasonable level?
Some setting in deployment option, or similar ?
Also, I have not yet tried it on a real Android device, but on the emulator application runs very slowly (never-ending Oracle splash screen on startup), on a computer with i7 processor with 8 GB RAM
There is a minimum size that will be required (about 15mb) which is the ADF Mobile container which is where your application is executed on the client, and you won't be able to go below that one.
Note though that this doesn't mean that a 2 page hello world would be 2*15 but rather a small addition to the first 15mb.