@JK_ 's Switch overclocking app Freebird has just received an update, marking the release of version 0.9.1 (beta). The new version attempts to fix the sleep mode bug, adds a new GUI for its Freeset companion app, includes four new profiles (as well as a Global one which takes priority above all others), gives you the choice to maintain your defined clock speeds when waking up from sleep and also allows you to save your config between reboots.
All of the new features and changes mentioned above can also be found in the official changelog:
Freebird 0.9.1 (Beta)
Attempted sleep mode fix
Ability to control whether clock speeds are maintained when waking up from sleep
New GUI
4 Different power profiles + Global profile that overrides all.
Ability to save config for reboots.
Click to expand...
The developer also advises users to post suggestions, issues and ideas on the official GBAtemp thread (linked below). For Atmosphère users, it's highly recommended to update to version 0.8.6 (or later) before installing the homebrew, as it includes a fix for a bug that was present in previous versions which would lead to crashes when overclocking the CPU.