Might be ok
In a pinch this will work ok. Only measures 3 inches (no touch-and-slide option). It does offer a slider within those 3 inches to measure accurately, but you have to have your finger directly on the "marker." You cant get the "marker line" directly against the item measured because you cant get your finger that close to the edge of the item (when you have the item directly on the device screen). Would help to have a "handle" which extends beyond the marker line.
Flybabyapril about
Ruler®