You can get the weekly drop by leveling up in csgo, but it's also possible to get graffiti and cases. But there's still a chance of skin. Other than gamehag, you can try others. All I can say is like csgopoints or clickloot, they are both legit and gave me skins, no gambling nothing. Just do tasks, buy stuff from there and yeah. Not sponsored but just thought you want to know.
there is one more app on Android, idk about IOS, named GoCases, you are getting points by playing other games and then opening the cases.
Open cases or buy them on the marketplace.
in 3 steps
Choose the game that interests you and play itfor free.
Every game has some quests for which you will receive Soul Gems.
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
You know that on Gamehag you can get real rewards for free, right? Join us, complete walkthrough and get your chest!
The only way I know to easily get CSGO skins is either from opening chests or to use gamehag.