Fixed the font resizing, now the timer should look correct, thanks for your patience.

Added 'Beep' to the sounds.

Stopped using loops to play sound samples, now sound clips are dedicated one, two and three whistle blasts.

Added 90 seconds to the 'Timer Length'.Adjusted the picker style for 'Timer Length' and 'Timer Yellow'.

Issue with allowing the device to sleep after timer had finished when the sound was set to off.

Minor UI changes, Timing code updated, whistles blasts corrected, and sleeping of the screen is now disabled whilst the application is running. Thanks to Hannah for the feedback.