There are quite some companies selling android head units. I myself have now my 3rd Joying head unit.
You need to check with the several manufacturers which options you have. Most 7", 8" and 9" units fit inside your dashboard, but you have to look which manufacturer has one specifically for your brand, or the best "universal" that fits your truck's dashboard best. I'm afraid though that they do not have much "brand fitting" units for trucks.
The 10.1" models (mentioned in the previous mail) almost never fit your dashboard and they are indeed positioned in front of your dashboard. You can consider that ugly, but now that I have the 10.1" I'm really happy with it.
My latest one (1½ week now) is also a 10.1" single-din unit with 2-din bracket in my Skoda Octavia. Previous ones were 8" models fitting in my dashboard.
See attached (reduced) images.
The big (Chinese) brands are
Dasaitu (Hot audio),
Joying, Seicane, Atoto. I would stick to one of those bigger brands as the "unnamed" ones most have bad support.
You can also buy a Pioneer, Kenwood, Sony or Alpine, but most of the time they are 3-4X as expensive, indeed of better quality, but sometimes also with questionable support.
Skoda delivers 2 units: 1200 euro and 1900 euro. This Joying one in the images is 466 euro with IPS-screen and it fits my needs perfectly (The previous 8"ones were 289 and 329 euro). As you can see: I run a specific "car launcher" on it (carwebguru, but there are others as well) with big buttons etc., but you can also install Nova launcher or whatever It is android, so you can indeed install almost any app you like.
I mostly use OsmAnd+ for it for its customisabilty (normal car profile with increased heuristic coefficient and caravan profile), but use MagicEarth for long drives where I want to know traffic info. But any Android nav app will function.
Success.