Glad to see the interest and suggestions, hbib.
Many tournaments have a small fee to enter if the player hasn't attained that league ranking this season.
So my son is in Silver, at the moment, which gives him free entry to most Silver, Bronze and Novice tournaments.
If he wants to enter a Gold tournament he'll need to pay an entry fee. They do this to prevent hundreds of people with weak cards from entering tournaments they're unlikely to win.
Did you mean a gold card every 20 daily quests?
Mobile apps for android and ios are on the way. The devs used the SMTT token on their Steem Engine exchange to raise $100,000. A big chunk of that will go to mobile app development.