From Benjamin Judkewitz:
I needed an IR viewer to see a Ti:S beam and was really surprised to find that most viewers still sell for > 1000 € (or $). Visualizing NIR used to be really simple with smartphones (enabling public installations like this one by JPL/NASA), but that was before nearly all makers started to include IR-stop filters. I recently found car dash-cams to be a convenient solution. They don’t have IR-filters, have small screens, are portable – and ~50x cheaper, for example this one.
Baby monitors that have a night vision mode might work too.