Here’s a full repo listing third-party stuff for Discord including clients. https://github.com/Discord-Client-Encyclopedia-Management/Discord3rdparties
Spoiler
None of them exist on Android. You have Discord clients mods like the recommended pre-react version, Aliucord which while outdated (But still working and supported by the project !) fix the slowness issues of the current version.
Vencord has a proof-of-concept WPA app too but it’s still mostly just browsing the main website so it ain’t ideal.
I would like to point out Beeper https://www.beeper.com/, which is Matrix based and aim to easily use their self-hosted (Or your self-hosted !) bridges to different services, including Discord ! Not ideal outside of small servers or just DM’s however (but you can customize which synced servers you want in it).
You could just also use your own VPS but i digress. It seems they plan on keeping their app proprietary with just the bridge tools to be able to be used with their app. (You could do use the individual matrix-bridges services however as an alternative but again, Beeper seems to be the only service that offer such hosting for direct usage)