Well, I see on the Instragram API documentation there's this section it actually works for your intentions.
It gets you this kind of JSON object with all your followers.
{
"data": [{
"username": "kevin",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_3_75sq_1325536697.jpg",
"full_name": "Kevin Systrom",
"id": "3"
},
{
"username": "instagram",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_25025320_75sq_1340929272.jpg",
"full_name": "Instagram",
"id": "25025320"
}]
}
Now, you only have to get a valid ACCES-TOKEN. Please reference:
How to get an Instagram Access Token