Back in the day, I had a phone (can't really remember what kind it was) that was running Android 6. Every time when i would click on software update in the settings, it would say "your device is up to date." However, when browsing online i found multiple (LEGIT) sources with Android 7 stock rom for that particular model. I am not talking about custom roms, it was the official firmware. Interestingly enough, it was the same situation with my tablet. I never had a chance to flash my phone or tablet with this android 7 stock rom to see if that was legit, but it left me wondering - is it even possible to update your android device by flashing stock rom even though the device says "your device is up to date" when you check for official update in the settings.