Assembly app is one of the most productive and professionally presented apps I have seen. I got information about it via @uxigers on Instagram. The great thing about it is that the free version has plenty of tools and resources to work with. You can then have the option of purchasing in app extras to further enhance what you are doing. The video gives a good overview of the sorts of things you can do. It is focussed on design and layout so it does have the snap to grid option which you can enable as you wish. The app also comes with a sound tutorial suite so that you can learn how to use different aspects of the app and set yourself right when it comes to using the app. It makes excellent use of the attributes of tablets/smartphones and so has brought us into the 21st century in its approach and intention. The more you know the better you are with this app. It teaches you to refine and improve your skills and create something of good quality. The Assembly app site is well laid out with plenty of information to help you get started. You can download it here from iTunes. There is a review here on Stuff which looks at it and then gives you other ideas of how to use it. Assembly is intelligent design because it functions well and anyone, no matter their level in graphic design can enjoy using this app. It means you can create and customise your own pictures, you can create layouts for apps and web pages, you can just use it as a sketch pad and playground for your ideas. It really is a productive, helpful, well thought out educational app.