Flycast

Flycast is a Dreamcast and Naomi emulator for Android devices. It runs most Dreamcast games (including Windows CE ones) as well as arcade games for Naomi, Naomi 2, Atomiswave and System SP.
No games are included in the app so you must own the games you use with Flycast. Or you can play free homebrew games available online.
You can play your Dreamcast games in high-definition and wide screen format. Flycast is packed with features: 10 save state slots, Retro achievements, modem and LAN adapter emulation, support for OpenGL and Vulkan, custom high-definition texture packs, ... and a lot more!
Flycast is free and contains no ads.