There is no reason for any Apple app to need my contacts so frequently. Example: yesterday I did not access calendar and it was not open, yet it accessed my contacts multiple times during a 24-hour period.
On the other hand, the Facebook app is only accessing itself and one tracker, inappcheck.iTunes.apple.com. Then again, Facebook places trackers all over the internet.
Badly behaved on iPad:
The Washington Post app. 218 total trackers, with each of these trackers contacting domains multiple times.
Weber Grills app: 121 trackers
Weather Radar (Impala Studios): 49 trackers
Reddit: 38 trackers
AccuWeather: 38 trackers
TripAdvisor: 30 trackers
Houzz: 29 trackers
IMDB: 27 trackers
Twitter: 17 trackers, but they have so many persistent tentacles in other websites and apps; one of the more insidious
Badly behaved on iPhone:
Google News: 778
Flipboard: 102
Amazon: 69
Twitter: 57
UPS: 47, including badly behaved trackers like doubleclick, google, facebook, etc.
SleepWatch: 33 including facebook, app-measurement, etc.
Chase: 33 including google
Shop: 32
AppAdvice: 30
Each tracker contacts its domain multiple times, not just one. therefore, the problem is significantly worse than the number of total trackers.
Relatively well-behaved apps:
Duolingo - 1 tracker