Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: Can you leave your iPad or Kindle Paperwhite in their case when using this product?
Document: This thing works great. It holds my iPad firmly at any angle. I have it sitting on top of another pillow when I lie in bed. If I want to type with my keyboard case, I just put the stand down flat and put it my lap. Very easy. The only real negative is the price. $35 seems like a lot to pay for such a simple product, so I knocked off 1 star. I'm still happy I bought it though.
I am really pleased so far when using my iPad , lying in bed or on a table top. I have neck and shoulder problems and it has helped me put less strain on those areas. I would recommend this product to anyone...even those without the neck or shoulder problems for prevention.
When my husband bought me a Ipad, I was so excited! After using it for a few days, we knew it needed some kind of prop. We would try putting a pillow under the Ipad but it would slip out. We got this Prop 'n go slim as a gift. One of my favorite things about this product, it has grip strips that hold the Ipad in place!! SO SMART!!! I love it!
I used to have to hold or steady the iPad with one hand while I used the other on the iPad, and the Prop n' Go Slim has eliminated my hand having to hold it in place! The Prop n' Go Slim has been really reliable and has made using the iPad a lot more comfortable to use! I really recommend this product for iPad users!The Prop n' Go Slim has also made sitting and reading a textbook for hours and hours a lot easier.
I ordered one of these for my wife to use with her Kindle Fire HD and it works very well for that after trying to pick a style/type of reader holder out of the hundreds of kinds on the market. I tried it with my iPad2 which is in a full case and it works well too. If you keep the adjustable tray in the flat position and flip it backwords it also works great for a lap stand for a full size laptop PC.
Purchased for my 89 year old Father in law that was getting hand and neck pain reading, well ok to be honest playing games, on his new kindle fire. Using this on his lap or on a table takes the weight off his arms and lets him read/play for hours. It is simple to adjust to the angle he wants and holds steady while he uses the touch screen. The Kindle stays in place and doesn't move around.
To say that I am in love with this incredibly simple product is an understatement. I use it for everything! It fits my Kindle Touch, Nexus 7, Samsung Galaxy Tab 10", Chromebook, work laptop, cookbooks, etc.I love reading my kindle in bed, but lying on my side and getting my kindle to balance on the cover was always a pain.
I previously wrote a review that stated this product was not one that  would highly recomment, but once speaking with a rep. and they told me how to use this product, I now like what I received and do use it. It was only cause I was using it backword LOL, good Product if you buy it.
I bought a competing product before this to replace the belkin viewlounge i had lost. i gave this new product(lap pro) a evening or so and it just wasn't my cup of tea. Tried this one as the bigger prop n go's just scared me off with their bulkiness and this so far really does address most of what i was looking for. first, it's much smaller on the padding underneath and that padding is a memory foam so it easily molds to your legs when using it like that.
Looking for a gadget to prop up your iPad, Kindle, or even a book? Look no further....this thing is wonderful. It is sturdy, compact, infinitely adjustable and comfortable sitting on your lap.
Answer: Sure, you can leave your device in the case. My wife (it's her iPad) has a hard case with a fold back cover and it has no problems. I've propped my iPad with a soft leather case on it and it fits too, though I don't do the hours of drawing on the desk she does. She remains delighted with the desk.