Uninstall programs that are not visible in Application manager I have an Asus Nexus 7 that is full of games that take up all 29 GB of memory. The kids installed these games, and they are not visible in the Application Manager. Perhaps they were installed in a different way. I found an OBB directory that contains a lot of gigantic files with the extension obb and names that are related to games, but I'm not sure whether I can delete them without damaging the system. Where I should start to find and remove games?
You can use alternative application managers available from the Play store, or even Titanium Backup if you are rooted.

secondly if you are rooted,


Download any root explorer,
Navigate to /system/app/ or sometimes /system/priv-app/ and manually
uninstall by deleting the packages (you may need to delete files
from android folder manually eg. obb files)
Reboot and you are done (optional)


If none of the above works,


Do a backup of apps and data using a backup manager (Recommended:
Helium for non root users, Titanium Backup for root users)
factory reset the phone, and delete '.androidsecure' and 'Android'
folder from external memory if exists.


Voila! you are done!