Creating an application for mobile phone is easy for a developer, but if you want to make this application available on a large number of phones...

Many difficulties may occur :

• Hardware differences : screen size, keypad codes, memory size, execution speed, keyboards, touch screen …
  
• Incompatible architectures : J2ME MIDP, Android, Blackberry RIM...
• Manufacturer libraries : NokiaUI ...
• Optional libraries : multimedia, bluetooth ...
  
• Different version of libraries : MMAPI 1.0, MMAPI 1.2 
  
• Incomplete or incorrect features : bugs
• distribution constraints : binary names
  
• Localisation constraints : languages
• Signature issues