Pwnie Express is a pretty awesome company, https://www.pwnieexpress.com/, you have probably heard of their Pwn Plug even if you don't recognize the company's name.
They have a new Pen Testing phone out called: Pwn Phone 2014
Product link https://www.pwnieexpress.com/penetration-testing-vulnerability-assessment-products/sensors/pwn-phone-2014-penetration-testing-phone/
They aren't cheap, but Pwnie Express also provides free downloads for the entire software suite they use in their products.
It usually take a little time for new product's software to be added, but they already have software for 2014 Pwn Pad, Nexus 7 based, available.
Download [Updated link 1/13/15] https://www.pwnieexpress.com/community/ if you want to use your existing Nexus 7, they should have the Nexus 5 download available in near future as well.
The downloads for DIY are listed under "Community Editions & Legacy Product Downloads"
If I can find the time this week, I will also track down current hardware accessories they offer, & update this post or make post dealing with accessories.
Meanwhile you can view hardware accessories I listed for the 2013 Pwn Pad http://cliffsesportcorner.blogspot.com/2013/02/pen-testing-pwn-pad-by-pwnie-express.html.
Probably newer options available for some of those products, but those should work.
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