This is basically a customized cell phone, with limited - but satisfactory - functions for business work. 

It will be a lightweight small device.

My view is that there is no need for a high-definition big screen, as the phone users are not concerned with watching high-definition video and images.

The screen would be mid-sized that allows good visibility of an on-screen keyboard and permits easy typing, whether with finger or with an attached or built-in telescopic pen. 

In addition to the basic functions of a cell phone, such as calls, messages, email, calendar, ..etc., it would also perform positioning & simple navigation. 

The Business-related features of the device are:

Market & Stocks monitoring, limited -but satisfactory- business social communication, payment processes, it would have a simplified text viewer (whether text, Word, or PDF), and also support for displaying simple graphs, tables, charts ..etc.

It would also be equipped with a simplified browser, with specified features for business-related purposes.

Simple browser can easily be made safer as well. 

As I used to make things clear in this " MY NEW IDEAS " blog, Two versions of this device might develop: 

The 1st would be equipped with ordinary recent coloured screens, but without very high - unneeded - resolution. 

The second version would come with reflective monochrome screen (as those of Garmin smart watches) which might be equipped with a small internal lamp (activated manually) for lightening the screen in dark or dim conditions.

The advantages of this 2nd version are two: 

1 - prolonged battery life and eliminating the need for frequent charging, (suitable for all-the-day outdoor workers) for instance.

2 - Ability to view the screen clearly even in strong direct sunlight, by virtue of its reflective technology. 

The target customers of this device are:  

Businessmen, Executives, Secretaries, Stocks brokers & dealers, Sales managers & representatives ..etc. 

It could be a promising product.