Ask HN: $5/mo VPS pay crypto for postage Rails app

I'm looking for advice. My app, at https://coinship.pro, takes crypto for USPS (soon worldwide) shipping, via 3rd party API at http://goshippo.com.

Can you recommend features the app needs? I'm also interested in partnering with a marketing specialist, and possibly another developer, if you want to work on the app significantly. The Shippo API has dozens of carriers worldwide. It has no revenue as yet. I'm not sure where to go from here. Thank you.