I use Palmer Performance
ScanXL Pro on the carputer. If you have a smart phone, they have an app called
DashCommand, $20 for Android $50 for iOS. The only other thing you need is a WiFi (iOS) or Blutooth (android) OBD device which you can get off brands for under $100.
What information you can get from the vehicle depends some on the model year. 08s and later are CAN and provide more information. I've also found that if I set the H3 up as an H3 I am limited to only standard PIDs. If I tell the program it is an colorado, I have access to the GM enhanced PIDs, along with the ABS and SAS modules.
ScanXL Pro includes the windows version of DashCommand and I think the features are the same for the other versions of DashCommand. You can get all the infomation the Bully Dog provides plus a lot more. As for Oil temp, I'm not sure, but when I set it up, I have a list of about 500 PIDs.