I can't get which libs i should use for developing an Android app that menages Google spreadsheet. I need connecting, copying, editing, reading from a user spreadsheet but i can't understand today which is the way.
Google Drive Api : https://developers.google.com/drive/
Google Spreadsheet Api: https://developers.google.com/google-apps/spreadsheets/
Google APi java client: http://code.google.com/p/google-api-java-client/
Which is the correct one?
Short answer: All three
Long answer:
You will have to use the new Drive API, which allows to upload, download and modify files in Google Drive. With this you only have limited operations on spreadsheets, basically download it or upload it.
The Google Spreadsheet Api allows to make complex operations in spreadsheets, like accessing data by row and column.
The Google API java client is a dependency in all Google APIs, it is used to authorize the connection in different ways, such as OAuth or service accounts.