True Skate is free as a part of the Google Play games sale. Can't recommend this skateboarding sim enough.
Although there are still some in-app purchases, you can play this game endlessly without having to spend a dime.
The following description is from the Google Play store:
"The ultimate skateboarding sim.
Note: True Skate only comes with a single skate park and contains additional content only available by In-App purchase. See below.
Features:
- Realistic touch based physics that give an authentic skateboarding experience.
- Deck wear. Scuff up your Deck.
- Drag your finger on the ground to push.
- A beautiful skate park to get lost in including ledges, stairs, grind rails plus a bowl, half pipe and quarter pipes. (Additional skate parks are available as an In-App Purchase)
- Slow motion.
- Rewind
- User challenges
- Replay viewer
- Global leaderboards.
Available by IN-APP PURCHASE only:
- Additional skateparks and locations.
- Street League Skateboarding courses.
Optional IN-APP PURCHASES: (The same content is also available for free by spending True Credits earned by doing tricks and finishing missions)
- Unlock all missions.
- Unlimited slow motion.
- Unlimited board image changes.
- Unlimited wheel color changes.
- Unlock lists
- Unlock Skateboard packs."
Not sure when this sale ends…