Is it possible to use any Python package within a Kivy program, and ultimately running it on an android device? for example - can I use the package "xlrd" or "googlemaps" on Kivy? If the answer is positive, How do I do it? normally I get an error message that says "No module named X". 
Thank you.
Yes you can. Just download the package you want to use and place it in the same folder as your main.py. Then import whatever you wish to use from that package. The packages will also work when you deploy the app onto an Android device.
Using various Python packages within a Kivy program