PixelFed uses the same federation protocol as Mastodon, which means Mastodon users can follow people on PixelFed and vice versa. You can try following a PixelFed account right now such as @Iancylkowski or @JoseMel or @connyduck
You can use PixelFed through a web browser, and there are also free open Android apps like @PixelDroid and FediLab (@apps).