Vendroid is not actively being improved. However, it still functions just fine and doesn't need any updates (it is not abandoned / discontinued).
For a more feature complete app, check out Vendroid Enhanced instead!
Vendroid is a custom Discord client for Android. The way it works is that it loads the discord.com website and injects Vencord.
Discord's mobile site is not very usable since it has many issues. As such, this is mostly just a proof of concept and is not actively worked on.
You are likely better off using other mods that specifically target the Android app, like Aliucord.
Visit the latest release, grab the apk and install it