Even though SurvAid's apps have tools that are specially designed for creating survey specific diagrams, some users just want to be able to quickly draw something themselves freehand.

Watch it in action on YouTube or see below...

The free draw sketch has an area where you can do just this, with a simple undo option and a button to clear what's there and start again.

Once you're ready, tap the "Done" button to save the sketch.

You can always open it up again later to edit it. The undo will still work, even after you've closed the sketch and then come back to it.