Salesforce 1 provides Offline Capability when using the Native App for iOS & Android including :

These capabilities are detailed in the next slides.

The left Panel proposes 5 “Recent items” tabs + Recent Events + Recent Tasks + Dashboard. These 5 tabs recent items can be cached for offline usage 

Salesforce 1 caches automatically the user’s most recently accessed records on the mobile. If the user wants to cache also recently opened records on other devices, he can force the App to cache it by pushing the Cache Now button in the Left panel > Settings > Offline Cache > Cache Now menu.

Salesforce 1 also allows to mark files that the user wants to keep available when he is offline. You just have to go with your mobile on a file and click the “download” icon on the bottom right corner:

Once on the Account he will :

Once on the Account Edit Form he will :

Once the Account is saved he can go to the "Recent Accounts" list and see that the Account is pending update thanks to the green arrow icon.

He will have the same information if he opens the left panel…

…and also when going to the Pending Changes Panel.

When the user is back online, the Pending Changes will apply automatically.

A notification is displayed and all the green arrows indicating Records pending changes are removed.

What happens if the user updates a Data that he shouldn’t be able to ?

If the user applies changes that shouldn't be done (such as modifying the Account Name), he wont be blocked when offline.

When he goes back Online, he will get an Error Message and the Green arrow turns to Orange

If he goes to the Record, a message explains the error, he can fix the issue and save again.

How may I create my Visit Report even if I didn’t visit the Account or Contact and it is not cached ?

Sometimes, you won’t have the Account Cached or you won’t have the Visit Reports of the Account Cached and you won’t be able to create your Visit Report from the Account.

If so, the best solution is to go back to the Visit Reports Tab and click New.

On the form you can then fill every information and because you are offline, you won’t be able to link the Report to the correct Account & Contact.

Nevermind, You can type their Name as you remember and validate, it will save your Visit Report Offline !

The green arrow indicates that the creation you did Offline is pending synchronization.

When going back Online, synchronization start automatically and you can get an error. Click on it to review the issue : In this case, the Account was not found and you can then search it and finalize the Visit Report and click Save.

Once done, the Visit Report is saved with the Account completed.

Notice that the Contact was automatically set from the Name because it was exactly written the correct way and there was only one contact with this full name.