FND&AD Tables

IMP Few Apps tables 

FND_USER-- No of users in the system
FND_PRODUCT_GROUPS
FND_PRODUCT_INSTALLATIONS-à Patch set level
FND_INSTALL_PROCESS
FND_NODES
FND_LANGUAGES
FND_CONCURRENT_REQUESTS
FND_CONCURRENT_QUEUES
FND_LOGINS- No of users logged in.
FND_ORACLE_USERID- when validating apps schema
FND_APPLICATIONS
FND_RESPONSIBILITY
AD_DEFFERED_JOBS
AD_BUGS
AD_PATCH_HIST_TEMP- Temp tables to store patch history
AD_PATCH_DRIVERS
AD_APPLIED_PATCHES
AD_SNAPSHOT
AD_SNAPSHOT_FILES
AD_SNAPSHOT_BUFFERS
Select * from v$FIXED_TABLE;  To know all the views