Not as far as I know. I don't really like their app, but it's nothing like
MDE. Plus the reservation is technically a Loews hotel reservation. I just hold onto the emails, and you can check them by entering it into the Loews site.
For some of the restaurants. Which ones do you have in mind? The ones you can you'll be able to see that you can on the website there will be a "click to reserve" button. Usually you can only do them 1-2 months ahead. I know in park we've only reserved Mythos and that's less than 30 days, but I think at 30 days you can call to make them. So you can call to make them. All the in park places, a lot of the citywalk, and some places in the hotels accept reservations. A lot of people say you don't need to make them ahead, but I always like to. Off the top of my head I know Toothsome and Cowfish don't take advance ones. Both will text you when the table is ready though so you don't have to stay super close if you don't want to.
The Universal forums will be helpful! Also if you've ever watched the DisUnplugged podcast they have a Universal edition and I'm sure there's been some in the past with tips and such.