HI Amr,
You can use SAPUI5 library for creating the UI.
Have a look at this blog:
Making Engaging UI on SAP MII with SAPUI5
Also this is the SCN space for UI5:
UI Development Toolkit for HTML5 Developer Center
Also SAP MII 14.0 SP4 has inbuilt UI5 Chart objects i.e. you can create UI5 charts objects just as applet chart objects are created and then use in your IRPT files.
Regards,
Rohit Negi.