With your USB connection from the Circuit Playground to your phone set, the Circuit Playground Express data can be logged to the phone.
You should also use the Google Play Store to install a spreadsheet (or other program of your choice) to capture data from the Circuit Playground Express acting as a HID keyboard.
As Android is Google-centric, the best option is to go to the Google App store and load Google Sheets if it is not already available. I note that Microsoft Excel is also available in the Google App Store, but we didn't try it!
The code can be either of the programs earlier in this tutorial. The demonstration will use the second example which includes plant soil moisture data in the fourth column of the spreadsheet. You can change the program to add or subtract data as desired.
Load your spreadsheet app and select that you want to create a new spreadsheet. Position the focus on cell A1. Switch the slide switch and watch the data flow.
This type of data capture is great for gathering data "in the field" or "on the go".