It's a really great controller, and one of 8bitdo's finest.
Here are a few tips for both Pro+ and Pro 2, because I'll admit, there's more to it that's not really that obvious when you first start using it. While there is a PDF version of the manual on 8bitdo's support page, I'm not sure if it's accessible or not, but here are some tips for both controllers regardless.
Turning the controller on + usage tips
To turn the controller on, you just simply press and hold START for 1 second, and to turn it off, you press and hold START for three seconds. By default when you first take the controller out of the box, it's set to Nintendo Switch mode. If you want to turn it on in either X-Input mode, DirectInput mode for Android, macOS mode, or back to Switch mode, you'd turn it on with the following button combinations:
START+Y: Nintendo Switch mode. In this mode, it emulates a Switch Pro controller, complete with motion controls and rumble, but lacks NFC functionality for Amiibos. It also can't wake up the Switch.
START+X: X-Input mode: Emulates an XBox controller.
START+A: Mac mode. Interestingly from what I've heard, the Mac sees it as a DualShock 4 controller.
START+B: Android mode.
The next time you power on the controller, it'll remember what mode you last had it in. For example, if you last used Switch mode before powering it off, it'll be in Switch mode the next time you power it on.
The Pro 2 doesn't use those button combinations, instead there is a physical switch on the back of the controller with four positions; S for Switch, A for Apple, D for DirectInput, and X for X-Input.
Both controllers will emit a short vibration when they're connected via Bluetooth. When they're not in use for about 15 minutes or so, they'll power themselves off to save battery power.
Turbo mode
The controllers do have a Turbo function. To activate it, there's a Star button under the D-Pad. While you have the Star button held, press the button you would like to activate turbo on, then let go of the Star button. Essentially, when Turbo is activated for a button, it's like you're rapidly pressing the button over and over again. To turn Turbo off for the button, you'd do the same steps that you did to activate Turbo mode on that button.