It seems that you need some assistance in order to get some information about how the Slingbox works and how it works with the supported devices.
If you have the iPad, iPhone and Android phones, your best option is to get either the Slingbox SOLO or the Slingbox PRO-HD. The following links will provide you with all the information about these products.
The main differences among these devices are that the Slingbox SOLO will allow you to control one device at the time and it will allow you to stream the HD channels but not the HD quality.
On the other hand, the Slingbox PRO-HD allows you to connect up to three TV sources and it also allows you to stream the HD quality. Besides, it has an internal tuner that offers you the option to split the TV signal out. You only need to place a splitter on the coaxial cable that comes from the wall. Then, you will send two lines from the splitter: one goes to the cable box or DVR and the second line goes to the Slingbox PRO-HD coaxial input.
These connections will offer you the option to split the TV signal out, however, whoever uses the Slingbox coaxial connection will get only the basic cable service channels.
Regarding the Mobile applications, I encourage you to check this link in order to get all the information about the supported devices.
I hope this information helps you to clear out any doubt you might have about the Slingbox, how it works and how to take advantage of the available features.