@dhamlinmusic For me, the one which is most useful while not being in the store is Global Extension
https://github.com/paulber19/NVDAExtensionGlobalPlugin
No idea why it isn't in the store but it's stunning in all it does and has been available for quite a few years now. IBMTTS is not in the store, but works well, as do many of the other eloquence add-ons
https://github.com/davidacm/NVDA-IBMTTS-Driver
Obviously, Remote Companion
https://github.com/gozaltech/NVDARemoteCompanion
isn't in the store, it's not an add-on, but it's very useful for those of us who want to run a bunch of machines from one keyboard.