There aren’t (m)any lightweight captive portal solutions out there for us, except a few clumsy heavy or badly maintained projects together with heir professional counterparts in routers better than home-grade. Captive portals are cool and useful, read on how to build one, including video demo.
Build a OpenBSD wireless access point that redirects any client request for any website to a website of your own design. With a little imagination you could adapt this technique for more nefarious purposes – but that is not something we endorse here. Something more applicable to our kind may be to use this technique to do basic DNS based filtering, ad-blocking or something along those lines.
Maybe some will enjoy this simple console based wireless network manager i use on my OpenBSD Box to connect to the different wireless networks i come across during the week. 4NU558BUVMKY