Vermouth has been released in version v2.3.1.

After version 2.3.0, the update fixes a critical bug that could wipe out your entire game list (apps.json) if power was lost during a save. Saves are now atomic and properly flushed to disk, and leftover files from earlier versions are recovered automatically. The update also adds a new automatic setup wizard on the welcome screen that installs GE-Proton and umu-launcher in one click.

New

• Automatic Setup on the welcome screen - a new button that downloads GE-Proton and umu-launcher and sets them as your defaults in one click. Manual setup is still there if you’d rather pick versions yourself.
• Install a Game button on the welcome screen - sits next to Add a Game and Import from Steam for quicker first-run setup.

Fixes

• Fixed a power-loss bug that could wipe out your entire game list (apps.json). The save was writing safely most of the time but had a brief window where the old file was deleted before the new one was fully in place - a crash or power cut in that window meant losing everything. Saves are now atomic and flushed to disk properly, and the app will recover automatically if it finds a leftover file from before this fix. Fixes #86
• Fixed fetching ROM files from RomM.
• The view mode button (grid/icon/hero) now behaves the same whether the sidebar is pinned or not, instead of the unpinned toolbar only opening the menu.
• Removed the “Don’t show me tips” checkbox from the welcome screen - it didn’t do anything useful there.

Source: GitHub