To switch to a different eBay account please follow these steps:
1) Go into eBay on a desktop or laptop to revoke our 3rd party Authorization. Log in to the account you DON'T want to use and go into: Account> Personal Info> Sign In and Security. Then scroll down to the bottom of the page to Third-party app access> Revoke SellHound.
Here's the link:
https://accounts.ebay.com/acctsec/security-center
After you click revoke be sure to select "Apply" so it will be saved!
This should revoke your token with eBay on the account you don't want to use.
2) Click the "Person Icon" 
at the bottom of the screen and log out of SellHound.
3) Delete the SellHound App on your phone
4) If you are using an iPhone, go to Safari on your iPhone, and go to eBay.com. If you are an Android user, go to Chrome on your cell, and go to eBay.com. Log out of eBay. Log in to the account that you want to use on eBay.com. (Do not use the eBay app! Close the eBay app on your phone. Use Safari or Chrome as a browser when logging in and out of eBay.)
5) Download the SellHound app. Log in to SellHound. When you are ready to submit a post it should ask you to log in to eBay. Select the eBay account that you DO want to use.
This should do the trick but if not, please write to support@sellhound.com for further assistance.