Update 6/1: The Athena wallet app is not capable of splitting your bitcoin held as of August 1st, 2017. We recommend following these instructions to log into the Edge wallet and split your coins. If you didn’t hold bitcoin in any wallet as of August 1st, 2017, you don’t need to do anything.
Download the Edge wallet using the links on their site and simply login using the same username and password you are using for the account that held bitcoin as of August 1st.
It should login and show your existing Bitcoin internal wallets. Pick the wallet that held bitcoin as of August 1st and tap the three dot menu to the far right.
Select Split from the menu and confirm that you want to split that wallet.
You should be given a new BCH wallet with the same name as the BTC wallet you selected. The app will automatically find and display your Bitcoin Cash balance.
Repeat steps 2-4 for any other Bitcoin internal wallets which may have held BTC as of August 1st.
For Bitcoin Gold and all other post BCH forks you will still have to use the manual instructions below. You will need to substitute a Bitcoin Gold or other compatible wallet (Coinomi will work in many cases).
Note: These are our original instructions for splitting your BCH manually from an Athena or Airbitz wallet.
Athena Bitcoin app and Airbitz app users are encouraged to read the guide linked below from our technology provider, Airbitz.co. Other wallet users will want to contact their wallet provider or consult this handy guide from Coinomi. Be warned that no matter which wallet you use, this is an involved and technical process. Please read through the instructions, first, and then follow them line by line very carefully:
Option 2: Using the Coinomi app to acquire your Bitcoin Cash
In addition to the Electron Cash wallet used in the above guide, which is primarily a desktop wallet, testing here at Athena has revealed that you can also use the Coinomi app to access your Bitcoin Cash. Coinomi is a multicurrency wallet you can run on Android mobile phones alongside your Athena Bitcoin app. Using Coinomi, you could have your Bitcoin and Bitcoin Cash in two separate wallets on the same Android device. Here's how to do it:
First, follow the Airbitz guide above through all parts of Step I and Step II. Most likely you'll need to access the Airbitz Recovery link using the web browser on your phone and switch between that and the Coinomi app. By this point you should have already swept all your Bitcoin (BTC) to a new wallet within your Athena app and see that transaction inside both wallets.
Download and install the Coinomi app from the Google Play Store. You'll need to write down the recovery phrase on a piece of paper and store that securely (just like your Athena user/pass). Type in a password for the wallet.
Select "BitcoinCash" from the list of coins presented to you and press Finish. Agree to the terms.
Go to your new Bitcoin Cash wallet and tap on the three dots in the top-right corner of the screen. Select "Sweep wallet" from the resulting menu.
You're at the point where you need to paste in your first private key from the Airbitz recovery page. Remember, you're looking for addresses on the recovery page that match those on the list under "Source" in the Advanced details of the transaction you just made in Step I (see Step I, part 10 of the Airbitz instructions for a visual example).
Find your first matching address on the recovery page and click the button to the right to show the private key for that address. Copy that private key.
Switch back to the Coinomi app and paste that private key into the field on the Sweep paper wallet screen. Tap Next. It should show the Bitcoin Cash balance of that address. If it doesn't detect any funds, go back to the Airbitz recovery page and make sure you are copying the private key from the correct address (matching one of the "Source" addresses from the Step I transaction).
If Coinomi finds a Bitcoin Cash balance go ahead and proceed to sweep that into your new Bitcoin Cash wallet. This will take possibly several hours to confirm on the Bitcoin Cash network. In the mean time you may repeat instructions 4-8 for every remaining address showing under "Source" of the sweep transaction you created in Step I. When you are finished you should have an amount of Bitcoin Cash coins equal to the number of bitcoins you had as of August 1st.