Using xdrip+ offline via a loop?

Again as there is overwhelming info on the net and I'm very new to xdrip+ with miaomiao and libre with nightscout for reports....


I'm now in need to know.. 

How I can use the above offline? Is it tweaking settings within existing xdrip+ app or adding yet another app to partner xdrip+ which is why I'm writing this ....as I'm confused ha! Help most appreciated 