Thanks for posting -- and congrats on your first post!
I think we need a little clarity here, my understanding is that when you are referring to data points --you are talking about data sources. Both are concepts on the platform; A data source a single time-series stack of data, and a data point is a single entry into that stack. This is a minor semantic note, but it makes a big difference if you are trying to create more(or either).
To answer your question, you can definitely have your Android app create new data sources, without you needing to log in to the web-application. To create data sources from the android application you can use the platform RPC. The application is already using a shortened version of our javaonep library and is custom creating full RPC requests on-the-fly in the main activity. Details on the javaonep library will be linked below.
You will have have to program the app to call the 'create dataport' procedure. Inside our back-end platform we call data sources 'dataports'. Please refer to this link on how to format your create-dataport call: http://docs.exosite.com/rpc/#create-dataport
You can see in the highlighted text below how the code in the main activity is putting together a read procedure. You would only need to emulate this process to create data sources, or if you are looking long-term include the javaonep RPC bindings into your Android app.
Github page for javaonep: https://github.com/exosite-labs/javaonep
The list of all procedures available to you can be found here: http://docs.exosite.com/rpc/.
I hope this helps -- Thanks,