So someone just gifted me a used 1st gen iPad. What apps should I be checking out?

interested in ALL recommendations, but also specifically for things that make media very accessible (will be using for video when we travel with young children) and kids and general audience games. Also will likely use it as an e-reader and for internet and email, etc..

Also, anyone have a keyboard case that they love? I like my friend's zaggfolio case, but it's only for iPad2 and iPad3.