Finding tables & columns at risk of hitting max value of int

I just took over a medium-sized postgres database and the team has been surprised with many tables hitting their auto-incrementing id int max limits which triggered unscheduled downtime to fix. Does anyone know of a simple tool to help check all tables/columns and easily find which are at risk of hitting the int max limits? I'm sure we can come up with a script to check, but I remember reading somewhere of a tool to help me identify potential issues exhaustively.