Can we completely replace OnStar Functionality?

[mortoneccc]

I just bought a 2013 GM car and found it came with this wacky OnStar system. The functionality it provides is useful, but involving some external service provider for it is like in the 1920s having to talk to a switchboard operator to place a phone call. I think technology has similarly advanced a bit since OnStar was invented! So, I'm looking for a unit that I can replace the OnStar box with and will do [most of] the following:

GPS using the existing touchscreen display (instead of having to call OnStar for directions)
Send car diagnostics to my phone (instead of to OnStar)
Use my phone to call an emergency contact number (instead of OnStar) if the airbags deploy
Let me unlock my car from my phone when standing within bluetooth range (instead of having to call OnStar)
Hands free calling (already present in the car but worth mentioning)

Is there a unit like that? If not, why not?