[Mobile] Counter Sample Application

• The CounterApp defines 3 widgets in its UI specification: #counterText, #decreaseButton and #increaseButton
• The widgets used in this example are MobileTextWidget and MobileButtonWidget
• The method #constructEventsTriggered is defined in class side to answer an Array with custom counter events:

  ! MobileCounterApp class methodsFor: #events !
  constructEventsTriggered
      " Private - Return the smalltalk events managed by instances of the receiver. "
  
      ^#(#increase #decrease) , super constructEventsTriggered! !
  

• Both #increase and #decrease methods are defined in instance side to modify the counter behavior