Peak Flow

Invalid date

* New export function. You can now export all or a range of data and save it to the local SD card, save it to cloud storage such as Google Drive or send via email etc. This function is accessed via the settings menu. Requires permission to write to external storage.

* Graph shows date label using correct format for current locale.
* Midnight readings are now shown correctly when device is in 24 hour mode.
* General bug fixes.