How to know a friends who achieve this achievement?

Cant find the way to display friends, who achieve it, on achievement page.

/USER_ID/achievements - returns users achievements
/FRIEND_ID/achievements - returns one of my friend achievements
/APP_ID/achievements - returns list of defines

Help me please! Do I need to do many requests for each my friend (I think it is not good way)?

Solution

Yes, you need to retrieve the friends' achievements individually.

You can call /achievements?ids=[CSV_LIST_OF_FRIENDS] though - and calling /[USER]/friends?fields=installed will show you which friends have the app installed to help you limit the number of IDs you need to include in the CSV list in the first query.