PS! Chrome Sync

psgcsync

Uses Google Chrome's sync storage to save your Pokemon Showdown teams in your Google Account. Synchronizes teams across all instances of Google Chrome, so you can use your teams wherever you use Chrome. Periodically saves Pokemon Showdown's local storage to Chrome's sync storage and reads the sync storage to update your team list whenever PS! loads. WARNING: On first use, the extension will save all of your teams to the Chrome sync storage. Any teams stored locally on other devices will be initially lost, then all devices will be kept synced.

Screenshots from Chrome Web Store