xDrip+

xDrip+ is the most widely used open source app for diabetes care and treatment. Developed by the Nightscout Foundation, this app allows you to sync your glucose sensor and track your glucose levels with graphs. At a glance, you can check your current glucose levels, your glucose over the past few hours, and your glucose on any given day.

xDrip+ uses the data it obtains from your glucose sensor to generate statistics and make predictions. For example, if it detects that your glucose is starting to drop, it will give an estimate of how much time you have before reaching hypoglycemia. To do so, it uses your average glucose level over the last few months to calculate the glycosylated hemoglobin (HbA1c).

xDrip+ is fully customizable, so you can choose the prediction algorithm and data measurement. You can also customize alerts in case of hypoglycemia or hyperglycemia.

xDrip+ allows you to sync data from sensors from several brands, either via Bluetooth or NFC. From xDrip+, you can also send data to other devices such as wristbands or watches, as well as sync it to your Nightscout server on the cloud.

So, if you have a glucose sensor and want to make use of detailed graphs, alarms, and more, downloading the xDrip+ APK is the best option out there.