With all of the stolen truck threads lately, I was curious about this. All of the NEW trucks that I have bought over the last 20 or so years have been GM products. By using the OnStar ap on my phone, I can pull up the location of my truck any time. Do the other manufactures now offer a similar service? I know that you can buy an OnStar system now and retrofit it to almost anything. I wonder if the aftermarket one has as many functions as the factory installed system. Might be a wise investment for a truck without it.

Sure they do...probably more...check out the viper alarms smart start system....you can do all the same things as the onstar like get diagnostics and vehicle location, remote start etc.....but it also lets you add features to the system like rolling up you windows or closing the sunroof or what ever you basically think you want it to do when hooked up to an accessory channel.
Back in the early 90's when i was installing alarms/remote starts for a living, the company Autopage/Prestige was working on a system like the above viper system....but they also had an LCD add on screen that you could send messages to....like texting is now a days but back then it was in its infancy and alpha numeric pagers where the big thing! LOL Man do i feel old now!

I had one of the first aftermarket remote start systems on my new 4dr tahoe in 1995. Had a lot of fun with it before people became aware of the option.