why so many apps downloaded from Google Play show incompatible?

[mazhangr80]

Hi, I am installing some apps on my nexus 7. I want some airline apps such as Delta, Alaska, and the Barcode scan app. I search them on Google Play, it already say "This app is incompatible with your Asus Nexus 7". Is it due the Jelly Bean system? Can anyone provide the third part .APK file to use? Thanks a lot!