GPS specific for RV's

I have the Rand McNally app for the iPad. I cannot recommend this. It sent me through a busy business/strip mall in Tuscon only to send me to a NO LEFT TURN intersection to turn left at. Going past the intersection left me no opportunities to U-Turn and to smaller and smaller roads. I ended up unhooking the towed and turning around in a small housing community. Then I find out that there was a direct RV-friendly route straight to my CG from the HWY that I was on originally if we would have stayed on it 8 more miles. The app also thinks I am "off-roading" it quite a bit during a highway trek. If I have to use a mapping unit plus a GPS... the GPS is not worth it to me. These aren't isolated events. All too often it sent me on routes that aren't RV-friendly and I feel that I need to always back up this app with other mapping programs in order to verify that we won't be stranded without options.