This app is very helpful for those who are working in the Field of fabrication of Tubular heat ex changer, Boiler or any other process equipment where heat is transfer by shell & tube types of arrangement. This app is most useful for those who are Production engineer,Quality Engineer or Any Authorized Inspector those inspect Tube sheet to Tube Expansion joints. This tool will best suited for faster calculation of % of Tube Expansion or Thinning of tube wall thickness.