Also there's the https://github.com/karlicoss/HPI library, which you could build on, though it mainly relies on data dumps from the different services instead of crawling and fetching through APIs, which is why I didn't use it. Keeping up with API changes is bad enough, I don't want to deal with undocumented dump formats...
But don't let its attempt at a friendly README fool you, it's personal-grade software of "works-on-my-machine", and barely, quality.
If you want to look at something more polished, I think https://github.com/amirgamil/apollo and https://github.com/thesephist/monocle are worth taking a look.
Also there's the https://github.com/karlicoss/HPI library, which you could build on, though it mainly relies on data dumps from the different services instead of crawling and fetching through APIs, which is why I didn't use it. Keeping up with API changes is bad enough, I don't want to deal with undocumented dump formats...