Play games
Choose the game that interests you and play itfor free.
Complete the quests
Every game has some quests for which you will receive Soul Gems.
Receive rewards
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
I noticed an issue concerning reaching this group with ideas and suggestions in a mobile application. In the "Forums" section, after swiping down, the automatic scroll bar of all topics from the "Game Forum" section is activated, so it is difficult (or little possible) to get to this group to read topics and write a post. Such issue has been tested on iPhone 6 and 7 and on Android 5, the problem is the same everywhere.
It would be nice if a user could reach the needed groups without any such difficulties.