To use your DEVONthink Pro or Server license for registering DEVONthink To Go, do the following:

1. Open DEVONthink To Go 4.
2. On the database list, tap the button with the three dots, then choose Settings.
3. Navigate to License.
4. Log into your DEVONtechnologies customer account.
5. In Settings > License > License choose the license you want to use and tap the checkmark button to register your copy.

Please note that your Mac license needs to be eligible for updates.

Data stored on your device is encrypted using iOS’ own encryption. So your databases are always encrypted and can only be read by DEVONthink To Go after you unlocked your device after a restart.

An additional app-wide passcode that can be different from your device’s passcode secures access to your data. Alternatively you can use Face ID or Touch ID. For usability reasons, individual databases do not have their own password protection, but their password is required to import them from a sync locations.

If these two levels of security do not suffice, e.g., for classified government documents, a specialized data vault, as provided by most government agencies, might be a more appropriate solution.

Spotlight receives the name, the first 16 KB of text content, the comment, and the tags for each item as well as metadata like the item’s type, its icon, and the creation and modification dates.

16 KB seems to be the internal limit of Spotlight (as of today).

The sizes shown for individual databases, for DEVONthink To Go as a whole, and in iOS’ Settings can differ. Here’s how they relate to each other:

1. The Info popover for a database shows the sum of the sizes of all documents in the database, regardless if they are downloaded to the device or not.
2. The Help popover shows the total of the data store folder on the device, comprising of the downloaded document files, the metadata database, the full-text index database, previews, thumbnails, all the files needed by sync, and some temporary files.
3. The iOS Settings combine the storage size used for all files in the folder shared by the application and all its extensions (the ‘shared container’), the files used to provide documents to the Files app, and the Spotlight index.

If you have just moved from DEVONthink To Go version 2 to version 3, the storage size shown in the iOS Settings also add the size of the old data store left behind by version 2. It will be cleaned up four weeks after launching DEVONthink To Go 3 for the first time.

Note that iOS is using the APFS file system. Copies of files and folders (‘clones’) are counted with their size but don’t take up any space unless one of the copies is modified. File and folder sizes on APFS therefore don’t necessarily represent the real number of bytes used.

Check DEVONthink To Go’s settings in the Settings app and make sure that Search & Siri Suggestions is switched on. Check also DEVONthink To Go’s own settings and switch on Spotlight if necessary. Then try to search for terms that you know that occur in the document, e.g. in its title. If still no results show up rebuild the Spotlight index (see the build-in documentation, chapter Appendix).

Unfortunately, there are no granular and accessible backups in iOS or iPadOS. The backup to iCloud is meant only for setting up or restoring a complete mobile device.

At this time, while sync is not intended as a backup, it may be used as a current backup of a database. Since the data is only useful to DEVONthink and DEVONthink To Go, it is not a true, product-independent backup, though.

Alternatively, you can export databases a files-in-folders to the Files app and back them up from there.

For a long time the USB port in iOS devices wasn’t available to third-party apps. We believe that synchronizing via the local network provides a fast and reliable method even for larger data sets.