I just bought a Twotogether card over the weekend, here was my experience FWIW.
I had my desktop and my cellphone and found that it really took the two working together to get things done. The application I filled out and paid for on my computer, and that's also where I found and cropped my two photos from my Google photo library. Then as you upload that info, you need to download an app onto your phone (or maybe two, I'm blocking here) and then they send confirmation codes to your email that need to go into your app (so again the computer came in handy here). Then you end up with the card in the app on your phone.
I used a Chase credit card and it went through just fine, no issues.