Quite simple to work out some of this yourself:

>Where are you hosting this site?

    $ dig +short a www.createamemo.com
    memo-gen.herokuapp.com.
    us-east-1-a.route.herokuapp.com.
    23.23.225.163

> What is your tech stack?

    $ curl -I www.createamemo.com
    ...
    Server: WEBrick/1.3.1 (Ruby/2.2.4/2015-12-16)
    ...

So, it looks like it’s a Rails app hosted on Heroku.