Two Iâm aware of:
Yojimbo, from Bare Bones software
Curio from Zengobi
They both have their fans, Yojimbo especially, because itâs been around for a long time.
However:
Curio has no IOS version
Yojimbo has an IOS version that syncs only via WiFi with the Mac; Mac to Mac sync requires a paid subscription
I havenât spent a lot of time with either but it seems to me that Yojimbo is good as a bucket for collecting information (similar to DevonThink) and Curio can provide a wider range of support, but at the cost of a tougher learning curve.
Iâve recently switched to DevonThink from Evernote and did some research before I did. Taking your points about the UI etc, it was still the best I found.