Twitter Follower Checker

We've coded our own algorithm using Twitter's API but due to the limitations of the API we can't pull all the Twitter followers of each account therefore we rely on a small sample that we pull for each account we analyze. The sample is in the hundreds and we take into consideration the date that each user followed the account.
Some of the red flags we look for are default profile images, account age, followers vs following ratio, percentage of unique tweets vs retweets, and others. For obvious reasons we will not reveal the exact formula that we are using.
Based on the tests that we've conducted we realized that almost every account has a small percentage of low quality followers or bots, therefore, we've adjusted the threshold after analyzing multiple accounts from reputable brands, and individuals.
If an account has more than 50% of his followers flagged as low quality we'll show you the percentage in red, if it's below 50% we'll show you the percentage in green.