eng-pad

This is an Android app, targeting Android 11, and specifically the following two devices:

1. The Supernote Manta (Android 11)
2. The Daylight DC-1 (Android 13)

There are a few features it needs to have:

1. It is organized around notebooks.
2. A regular notebook's page size is 8.5 x 11 inches. A large notebook's size is 11 x 17 inches.
3. The app features a grid of roughly 5 squares per inch. The grid is not visible on exported documents.
4. The app should allow pinch to zoom in and out.
5. There should be two pen sizes, corresponding roughly to a Muji gel ink ballpoint 0.38 or 0.5 pen.
6. It should have the ability to erase, or to select-and-erase.
7. It should have the ability to select and cut/move or copy/paste.
8. The primary method of input is an EMR pen.
9. The app needs to be able to export PDFs though the normal Android sharing mechanism (e.g. so docs can be exported to Dropbox).

The tech stack can be flexible. The safe default is Java, but if Kotlin or even Clojure or some other langauge makes more sense, it can be used.