For our paper - SENSING SLOW MOBILITY AND INTERESTING LOCATIONS FOR LOMBARDY REGION (ITALY): A CASE STUDY USING POINTWISE GEOLOCATED OPEN DATA, we used the Twitter Streaming API, it has many parameters to customize what you get and it's a keep-alive connection. In the paper there's the link to the source code we used.
It very much depends on your specific needs, budget, etc. You could use native analytics for each of the platforms. Facebook, Twitter, Instagram, they all have their own analytics. For Instagram, however, you'll need a businss account.
Still, these will all be separate analytics.
If you wanted to have everything in once place, I'd advise to test a few of the social media monitoring tools. I am being biased, but I'd recommend Brand24 (https://brand24.com) for starters. With a free trial, you can test different capabilities of the tool and then decide if it meets your standards and you want to go for the paid plan.
As with any other social media monitoring tool, you just choose the keywords that you want to monitor, whether it's your brand name, your product, service, a hashtag, you name it.
The tool collects mentions of your keyword and presents the data graphically as well as raw numbers. You can track the performance of keywords you track in terms of:
number of mentions
social media reach
social media interactions (likes, shares, comments)
sentiment analysis
location (only for Twitter and Instagram posts)
I'd also recommend testing other tools just to see which one fits your needs the best. Have a look at Social Mention, Brandwatch, or Sprout Social. Hope you'll find this answer helpful!
I'm working on Android project that tracks the frequency of use and time duration spend on social apps, if you interested to add your touches, I would happy to share with you. My goal is to publish a paper at the same field of study.
Ahmed A. Mostfa please do share more info with me. I am researching also for an upcoming paper regarding self image in social media from a symbolic interactionism perspective.