My UK network provider has a travel section on its mobile website on which it has national train information powered by National Rail Enquiries. It's free and live. Considering that you have to pay for some apps that provide the same kind of information (using NRE), you might want to check to see if your network has something similar.
The only thing it doesn't have is the ticket prices. For those, especially for long journeys, I'd look at 'thetrainline', as it gives you the cost of tickets provided by different routes/companies to choose from. They give the same service on their website, so you can check it first to see if they really do give the best information on prices. However, they don't provide up-to-date information on arrivals and departures. You can buy tickets through this app, too.