Anandsoft.com Released CCENT android app for mobile users.
https://play.google.com/store/apps/details?id=com.anandsoft.ccentexamsim105
AnandSoft CCNA Android Simulator:
https://play.google.com/store/apps/details?id=com.anandsoft.ccna301practicetests
AnandSoft CCDA Android Simulator:
https://play.google.com/store/apps/details?id=com.anandsoft.ccdaexamsim310full&hl=en
The free android sim will have 60 questions with answers and flash cards. Additional tests may be purchased, if required.
Disclaimer: AnandSoft.com is not associated with Cisco® Systems and CCENT™, CCNA™ are the trademarks of Cisco® and duly acknowledged.