Since you're asking for pointers and not a full code, I'll tell you what you need to do to be able to make this possible, which it probably won't be anyway.
You'll have to make a cross-reference to other peoples' twitch accounts with their facebook,twitter etc accounts so you know when said user follows you somewhere. Store those nicks and accounts somewhere and if they match award a point to said user.
To see if they have followed, you'll have to use sockets to read info from the urls. View the source page of the websites you wish to check info from and if it's not available there you'll have to ask their forums or read their guides to check their api to make requests from there.
