First of all, kudos for taking the step and developing an app. Its the right direction.
It does need some work. Yes, less is more, and a mobile app has to be simple, but this one is just too limited. Poor access to the graphics library, and very limited editing. OK for the barest of necessities, but little to commend itself. Not even a simple "select all lists" option for choosing all recipients.
Im sure connectivity with existing code has to be tough, but you might consider approaching this app as a new starting point. From scratch - just using your site as an online database to pull contacts from. Do this right, and people will prefer the app to the website. Fail, and a handful of folks with passion & good design skills will steal your entire next generation of customers. And that next generation is a LOT closer than you think. I hold some shares of your stock, and would rather avoid watching that happen.
So...a good first step, but I humbly suggest a running leap if you are serious about future growth.