Hello,
I downloaded a free version of the official FortiClient VPN App on the FortiClient.com site.
But I checked the VPN options and Preferred DTLS Tunnel can't be checked. Is there a limitation then to a free version? Asked my question at https://forum.fortinet.com/tt.aspx?forumid=12 https://pimion.com
Daniel, Software Engineer at Pinion

Hello Ignacio,

There is FortiClient​ that is supported for Android 4.1 and more recent versions. In case Google Play services are available on your  device the tricky part would be to obtain needed .apk file. Because it seems available via Google Play store only.

You will have to grab needed .apk file first and then install it on your device.
To do that you may use a APK Downloader Chrome extension on your computer or to use Apk Extractor app from Google Play on another device that have Google Services available.

Dmitry Prokhorov
Software Engineer, Kutir Mobility
Posted on behalf of Zebra Technologies