I'd suggest an offline database, distributed with the app itself.
And updating only when needed ( when new HASHES and GAME TITLES are added, check for updates upon loading app)
This way you'll also save bandwidth

even save more money

Someone cleaning up the database once in a while, if it stays online... that would be cool, people add BS.
function to select available Titles :
GAME TITLE (already in the apps database) | REGION | COUNTRY | HASH (automatically inserted by the app) | POSTERNAME |
This way you can update the database once in a while with new GAME TITLES.
REGION and COUNTRY won't change or need to be updated ofcourse.
I'm offering my help on this, because i think community based apps involve everybody to do a small part

Just my humble opinion...