Lemmur is a mobile lemmy client that I and @shilangyu have been working on for quite some time. It's supposed to give you seamless experience when using multiple instances.
It's available for android, windows and linux, although it is mainly targeted towards mobile devices. The experience on other platforms might be less satisfactory.
This is only an alpha release so not everything will be working, there are some parts of the app that aren't finished. But we believe it is usable enough for people to browse their favorite instances.
At the moment we would prefer to focus on fixing bugs rather than implementing arbitrary features so if you have any bugs or crashes please let us know in the comments or create an issue on github. Screen recordings are welcome (github now supports uploading .mp4 and .mov files), it's always easier to understand the problem through visuals rather than words only.
If you'd like to see a version for iOS on the apple app store or just generally would like to support the development you can chip in over on patron or buymeacoffee, which will help cover the $99 developer license.
Here are some screenshots of the app: https://imgur.com/a/B5XhhXQ