Hi there
I understand the core of the project but here are some points that I need to make. First, Do you provide a list of users on those platforms that this extension will be scrapping on? There needs to be a method of providing that starting point before going to the extension point.
Second, in order to compare images, you need to use some image recognition API (like that Google provides) and let it do it for you. The result will be returned to the user.
Third, I can implement the text matching with efficient algorithms, that is not the problem, but the problems are those 2 points above.
Anyways, feel free to hit me up so we can talk more about this. I am very responsive. All the best