The following Graph API gets the first checkin for each friend. How do you get the last checkin?
me/friends?fields=checkins.limit(1).fields(from,message,place.fields(id,name,location,likes,website,phone,description,checkins),tags)
Note that I can remove the limit but that is going to give me all the checkins which is not what I want.
You can try use checkin api by FQL. I see only one way: use multi query in one request:
1) select post_id from checkin table from your friends (author_uid) order by timestamp (desc)
2) select page_id from location_post table, where posts from query (1)
3) get pages info from table page where page_id is set from (2)
As result, you get last checkins, but issue: this checkins don't grouped by friends. For example, you can get last (by date) checkins, that have one user.