Bl4ckSh33p we don't have any signing enabled at the moment, all builds are returned in unsigned.
Debug builds can be installed on a device manually as is, and can be linked to a debugger ( not C3's debugger at the moment ).
Release builds must be signed before they can be used, and should be used for publishing to the store.
We have some size limits in place at the moment to protect the server from being overloaded, these are likely to be adjusted when we understand our system limits better but at the moment they are 40mb ( compressed ) 100mb uncompressed. If we start getting higher than this we might have to look into implementing APK expansion files for the runtime, as the play store has a APK size limit of 100mb.