I think there are very basic comsumer versions of EEGs that you can plug in to computers or phones. Example: https://www.amazon.co.uk/dp/B00LOQR37C/ref=cm_sw_r_em_awd_qrv3wb29EH7TE
But (although I might be wrong about this) they can't show much detail. It's less 'watching parts of your own brain light up' and more 'watching a graph of the total electrical activity in your brain'.
They're far simpler than an EEG from a hospital, let alone an fMRI machine.
I think it still could be used for biofeedback of some kind, it could be similar to that discussed but far more rudimentary. It could be useful for monitoring your own sleep (there are even smaller, simpler versions that can do that without being as uncomfortable).
I don't think this technology, although it's cheap and easy-to-use enough for the average person like me, can tell you which parts of your brain are specifically more or less active. But an advanced EEG can, because it can triangulate positions of the sources of the currents it measures, in the same way an ECG can physically map the heart (when in the hands of someone who REALLY knows what they're doing of course). So eventual upgrades to this kind of technology, providing more electrodes and advanced software that can approximate the work of the highly trained professional, might make that possible in the not-too-distant future. But fMRI and other advanced imaging like PET will not be small or cheap or safe enough for consumer electronics for the foreseeable future (probably a very long time if ever).
I might be wrong about any of that though, I didn't research it before posting so it's just what I remember from reading things in the past.
I'm no expert in this area by a long shot, but I have heard good things said in this subreddit about the Muse, as far as the cheaper consumer-grade devices go.
Curious, how does the Muse stack up against the BrainLink Pro? I'm a bit more interested in hardware limitations (e.g. number of channels, etc.)