i want a simple app to draw on ipad like if i was using a paper… but i need to draw rect lines and rect lines with arrows to indicate meassures. something like autocad… but simpler and cheapper
well since there is only one source for iPad apps… I suggest you start by there 
of course there is one other source, and that would be design and write it yourself 
and from past experience (iPad or not)… any level of “CAD” like app is not easy
thanks dave… i have already searched on app store, with no success.
Unfortunately, in spite of pretends by Apple that the iPad is a computer, it remains a gadget…
May be time to develop the app you need.
I had thought about porting my PaintDS app to the iPad… but since it would benefit mostly by using the “Pencil” and a lot of users (myself included) have the “non-Pencil” version… the level of precision with a “fat finger” wouldn’t be worth the effort
there is … “autocad” for ios !
also “autodesk sketchbook”
“A360”
“keyplan 3d”
“canvas sketchupbook pro”
your choice
anyone ever have a newton ?
its note taking app had the handiest drawing mode
you could scratch out a rough square & it would make it a perfect square
same for lines and circles & all kinds of other shapes
and then you could move them around to rearrange your drawing
very handy and an app for the iPad could easily do this