Hi wizardz, 

take a look to this: https://play.google.com/store/apps/details?id=com.odoo.OdooTimesheets 
or odoo crm is available on github: https://github.com/Odoo-mobile/crm
this app is base on android odoo framework, that let you customize everything which let you add every odoo model you need.

You can check http://www.probuse.com/blog/probuse-odoo-apps-25/post/mobile-timesheet-odoo-511