Truecaller is a mobile application, which is a worldwide number lookup service. Which means through this app you can find owner of any Mobile number without calling to that number.
Uploading photos (Images) and then tagging friends to it is common on Facebook. But there may be some pics you wants to untag yourself from. You may have any reason for that like, you don't like that pic, you are not in that pic, you are not looking good in that pic or you don't want your friends to see that pic or any other.
Do you any Image or PDF file you wants to convert into text ? Have you ever wonder to extract text from images? You can do this with online OCR tools. I listed some sites below and guess what these are all free (of course you can buy a premium tool too, but why to buy if you have a Free option)