First I'd like to thank you for the comment. You made me realize a mistake I made in mentioning JPay and Securus when I meant to say Global Tel Link and Securus.
As far as pushback from other companies, we haven't received any so far. There's nothing they can really do besides make their services more appealing. Currently, with Letters (our first app), it allows users to sign up, add their contacts (inmates), and then type out a letter and also are given the option to attach an image. Then we use a third party service, Lob, to print off the letter and send it. Given that we're just working with physical mail, there's absolutely nothing they can do to stop us.
One type of pushback we can receive is from facilities themselves. One facility returned one of our letters and said that you can't have anything in the letter that could be some form of encrypted message or symbol. In our case, that happened to be the bar code used by the third party service to manage their letters.
In the future, we'd like to also offer services like free video chat/messaging. In my opinion, we're not far from being able to offer those kinds of services. I can definitely imagine some sort of pushback happening in that space, but what kind specifically is TBD. I'm excited though, because if we can get to that point, we'll be literally transforming the system.