Update your git fork from the upstream project

Once:
git remote add upstream https://github.com/otheruser/repo.git

Every time:
git fetch upstream
git checkout master # your fork
git merge upstream/master

# Do not do this if your repo has more than one user:
git reset --hard upstream/master
git push --force origin master

(source)

Sync Google contacts with iPhone

iOS 7 should just work when you add a Google mail account.

iOS 5 or 6:
Settings > Mail, Contacts, Calendars > Add Account... > Other > Add CardDAV Account

(source)

How to sync over FTP

Don't re-invent the wheel.

1) Install rsync instead, which is designed with syncing in mind.

2) ftpsync was written a decade ago. Perhaps it has been updated since.

3) lftp syncs over FTP and is being actively maintained.

4) Perl package turbo-ftp-sync may also fit the bill.