This app offers a lot more than some reviews suggest. We use it daily for measuring job site conditions, and then sharing that information with co-workers. The marked up images create a handy reference that we keep on our server for everyone to access.
Moving the dimension lines can be difficult until you know the trick -grab the line between the arrowhead and the text box. Lengthen the dimension line if there is not enough room to grab, reposition the line and then return the arrowhead to the desired position. Easy once you try.
Its true, there no way to remove an errant dimension line. My work around is to move it to another location I need to measure or start over. Not that difficult.
The developer has been very responsive on technical support, and I hope they continue to revising this worthwhile app.