Netflix and LOVEFiLM have a new competitor in the form of Sky's Now TV service. In fact, over time, it will probably offer much more.Sky's Now TV differs from the Sky Go service, not least because it isn't free for TV subscribers. But the changes are much deeper than that. Available for computers and connected TVs, but more relevantly for us, tablets and mobile phones, you can 'buy' movies for between 99p and £3.49 for viewing or shell out for a monthly subscription, which costs you £15 and gets you 30 days viewing.The service focuses on movies initially, but will eventually include some of Sky's key TV shows and sports channels, which you can watch without signing up to a long-term contract. But when it comes to the movies, the selection could worry the established online movie companies.Sky is promising five new movies each week, 12 months before they launch on other subscription services. It will also offer three-quarters of the top 100 movies in the UK. But oh yes, you can only use it in the UK, so don't go thinking you can take it on your summer holiday, which is a shame. Licensing problems, we suspect.Check the Sky site for compatible mobile devices before you order. But if you like the sound of Now TV, you can sign up from today.