the LifeLog API is a RESTful API, meaning, you can, in theory, access it from anywhere as long as you can create HTTP
requests.
The authentication used is standard Oauth2
which also is defacto used by most APIs like Google, Facebook, Twitter etc.
Other than that, there are a couple of Android libraries available which can make your life a lot easier, wrapping the HTTP requests into simple Java objects and methods.
https://github.com/championswimmer/Lifelog-Android-Library
https://github.com/yaeda/lifelog-android-sdk
Disclaimer: The first library linked has been co-authored by me