Any open source Android users here?

Do you use a device with open source Android firmware? What device, which distro and what do you do with it? I have a Samsung tablet with LineageOS and apps from F-Droid. Other than displaying dire warnings about the unlocked bootloader every time it cold boots, It's great for a "recliner system": email, Web browsing, E-book reader and MP3 player. What do you have, what do you use it for, and how well does it work for you?