I'll admit,there are no good scooter apps available. There is the razor scooter app which gets boring after two minutes because there are a limited amount of tricks and the skate park is shocking. It could be a lot better, however it is free. Instead, you have to use alternative freestyle sports apps, such as skateboarding, BMX etc.
the first app I'm going to recommend is called touch grind BMX, which I'm sure many of you would have heard about and been on. It costs £2.00 or £3.00 I can't remember which one, and I would say its just about worth the money. The BMX is like a finger bike tech deck thingy where you put one finger on the bars to steer and on on the saddle to go forwards. There are a bigger variety of tricks than on the shocking razor app, which tricks such as tail whips, 360s, backflips, frontflips, etc. the graphics are the best thing about this app, they are really impressive. There are around 6 different courses each about 1 minute long, some a bit longer. I would like more freedom in the courses, and I would like there to be a skate park where you can just cruse around and practice tricks. I like the fact that you unlock new bikes, skateparks, paints etc as you complete the challenges, and I like the replay button and the fact that you can save the replays and put them on YouTube.
My favourite skatepark app is called true skate, a skateboarding app which allows you to cruse around a large skatepark, containing a mixture of street sections and massive park ramps. You can do practically every trick other than manuals, flips and maybe a couple of others, but I don't know cuz I don't skateboard. There are loads of grind rails and a massive bowl as well. Like touch grind BMX, this is like a finger board where you put one finger on the board to steer and the other on the ground to push with. I would recommend this app to any one, because I don't skateboard and I like this app. The only negative thing I have to say is I would like more skateparks, because just having one gets a bit boring, however they might update this. The challenges are alright, bit really hard however some are a bit more challenging. You get more points for doing impressive lines and you can unlock the slow mo with the points. I like this app and I would recommend it to skateboarders and scooter riders.