Why not make a weekly or even bi-weekly Medium update? Some short video snippets from the office, some new developments, the possible partnerships you are working towards etc. Keep the buzz alive, give people a reason to take a further look to ETT. Surely you can't be too busy to do this once a week or every other week? With the budget you have you could even hire someone to do this for you for a small fee on a regular basis.
Last update on Medium was in May, 1.5 months ago. And I think I know why the do it. They have the money and they don't care about investors, they don't need them for adoption. They will even benefit if the community will be dead, less people complaining about delays, nothing delivered, broken promises etc.