My old OBD2 code reader has disappeared. I noticed now there are many models available with various options. I have a 2001 RX300 AWD.
Any recommendation on a reasonably priced scanner which will give me some valuable info for troubleshooting.

 

It sounds like your missing unit was a basic code reader. I use a bluetooth adapter with the Torque app on my Android. I get fuel trims, tranny temp, coolant temp, and other useful info along with codes. Similar adapters (wifi based) work with iphone, although I have no experience with those.

I have bought Veepeak and Kitbest adapters and both work and are inexpensive.

 

Yes, like Lex said - for basic needs, a BT or WiFi connection and phone will do. Otherwise, for some depth, you need scanner with CAN BUS compatibility, to read brake and transmission codes.
HarborFreight actually has decent and well priced - we don't know your budget, so I am guessing, 100-150 range. They are big and clunky, but do the job. Have one for about 5 yrs now, no issues.
If you feel brave, sky is the limit on Aliexpress.

 

Love the Torque Pro.

Has anyone had any success using any other apps for individual tire pressure information?

I use the Tire Assistant app for the misses with her Highlander (which is ridiculous that it doesn't give you individual tire pressure), but that app doesn't work with my 09 IS. I just get all zeroes.

Any suggestions or are we just SOL with our IS's?

 

I have the BlueDriver. I like it a lot