How to build a tablet running only 1 app

so i need some help and i dont know if this is the right place to ask but here it is.
I need to build a tablet that runs 1 app only and uses wifi to update that app constantly, the app is the only thing thats going to be running when the device is started. so can someone tell me how i would go about doing this or atleast point me to the right direction??

Welcome to the forum.

Are you asking how to program one of the GHI .NET Micro Framework (MF) boards which are being discussed on this forum?

There are several GHI boards that could be used to build a device with a touch screen, that connects to another machine via WiFi, and runs a single application.

There is URL that contains a good starting point for information about MF development:

https://www.ghielectronics.com/support/.net-micro-framework

thats somewhat what im looking for. so since im running one application would i need things such as a motherboard, harddrive, ram, and a operating system?

I suggest you look through the GHI offerings in the Catalog section, and read some of the learning material at the URL I posted earlier. This should give you an idea of the capabilities of the device and what storage devices can be attached.

You need a main board and have to choose between SOM
http://www.ghielectronics.com/catalog/category/34
Or a gadgeteer board
http://www.ghielectronics.com/catalog/category/274
Hard drive would be a SD or µSD like
http://www.ghielectronics.com/catalog/product/271
Ram is on the mainboard and there is no real OS on the netmf devices just look at it as a driver between the c# interpreter (netmf) and the hardware.