Once all your accounts are entered, it's time to synchronize.

Account Heights
Zkool keeps the synchronization state of each account independent.
This is like your gmail accounts. If you have more than one, the gmail app downloads the messages of your current account. Your other accounts are sometimes behind[1].
In the screenshot above, you can see the various account sync heights in the red box. I restored an old account with a birth height of 2200000, therefore it is up to date to (the end of) 2199999.
Auto/Manual Sync
If auto sync is on[2], Zkool will occasionally check the current block height and compare it with the account heights. When an account falls behind by some threshold[3], Zkool starts synchronizing it.
If you want to start synchronization immediately, tap the sync button on the appbar (in the green box). This starts the synchronization of every account at once.
You can also synchronize a specific account, but first you have to select it.
Select on account by tapping on its row.