You can develop your own software using any platform or programming language you like, and use a Nimbits server as a back end for storing your time series data; taking advantage of all of Nimbit's services.
Most of Nimbits' functionality can be accessed using a REST API Interface and making simple HTTP post, get, put and delete requests. Nimbits supports using a secret key, OAuth, OpenID and Google Authentication.
Documentation on the REST API is available on the Nimbits Server Source Code page on Google Code under featured downloads:
Taking this a level down, I have a Java Jar file that all of our java based client apps use (including the Android App). This project: Nimbits4J.jar has all of the code needed to authenticate a request with Google, and make requests to Nimbits such as getting a current value, recording values, getting charts, history, creating points etc.
The source code for Nimbits4J is available here:
We do have a .net client package as well but it's not posted for download. If you'd like to get your hands on the .net client for Nimbits, just ask and we'll help you out.