Now you can join the Acala 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 Acala Crowdloan app
Enter the number of DOT you'd like to contribution (Minimum allowed 5 DOT), 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
After click 'Contribute', you need to confirm the transaction, and wallet password is needed.
When the transaction is confirm on chain, you have success contributed to Acala crowdloan.