Now you can join the Moonbeam Crowdloan in MathWallet for both mobile and extension wallet
For Android user, suggest install MathWallet1 version here https://mathwallet.org/mathwallet1/
For iOS user, please follow below guide to open dapp https://blog.mathwallet.org/?p=3462
First switch to Polkadot wallet
In the DApp list find Moonbeam Crowdloan app
Click the 'Connect to Polkadot.js' button
Confirm the wallet address, and click 'verify account', only pre-registered addresses are allow to move forward
Enter the number of DOT you'd like to contribution, note that the token will be locked till 2023/10/20 if it wins the slot, if not win it will be returned on 2021/12/16
Then you need to enter an 0x Ethereum address to receive the reward token, it can be your safe Ethereum wallet address (but not any exchange deposit address), you can use MathWallet to create one Ethereum wallet if needed.
After click 'sign and send', you need to confirm the transaction, and wallet password is needed.
After 1-2 mins, you will see the success message.