Apps Sources to build this image viewing app

[cubangt]

Here is a brief description of what im trying to build.. all im looking for is suggestions on the correct way to do it and what controls within the app will accomplish what is needed.

I have only built 1 or 2 apps for the android, so new to it, but am a software developer for windows and web.. so have programming experience and built my first simple app in matter of two days with 2 days of fine tuning after family tested..

New idea is for my sisters website to offer an app that will allow her client to view their photo session thru the app.. Currently on her site we have setup a "Photo Session" section that you login into and are allowed to view the pics of your session with her, and eventually will be able to order from the site.. currently its more of a preview area..

So for starter i would like to see about making a simple app to allow secure login into the session and view your images.

Can anyone suggest the most efficient way to accomplish a simple but secure way to login and view the pics on your phone thru an app. When viewing the site thru the web browser it works, but not the most optimal.

thank you